APPENDIX D

THE NETWORK VERSION

WHAT YOU WILL FIND HERE

     You will find information about the Network Version of CompuDance.  This Appendix tells what it does, what it does not do, how to install it, and some notes about using this version.

HISTORY/BACKGROUND

     The first version of CompuDance was written in 1984; published in 1987.  We did not anticipate at that time that there would ever be dance studios with two computers using CompuDance simultaneously.  In fact, the BASIC language we used to write that early DOS version was not capable of tackling the problem of file sharing.  Networking was in its infancy, and thought to be only for big corporate giants some day in the future.  So we wrote CompuDance to be as efficient as possible, to avoid overhead, to minimize the possibility of losing data stored in memory, and to reduce the number of times that files were opened and closed.

     When we began to write the Windows version in 1994, we decided to continue this philosophy.  One of the results of this was (and still is) that the structure of CompuDance couldn’t be easily changed to support more than one computer accessing files simultaneously.  The process of locking and unlocking files and opening files for either read or write access would necessitate a major program rewriting.  This is one reason why we have not created CompuDance to function in a networking environment.  Another reason has been that very few studios have requested this capability.  

     And so, the current published version of CompuDance (8.00.00) does not support multi-user access on a network.  That means that when a computer running CompuDance opens data files in a given year/studio, a second computer on the network running CompuDance will not be able to access those data files in that same year/studio.  The Windows operating system will display an error message (“Permission Denied”) and shut down CompuDance on the second computer.  It cannot handle two processes (computers or programs) opening and writing to a file simultaneously.

     The reason for the system error message is that in a multi-user environment where more than one user has access to the same data file simultaneously, there is potential for major data integrity problems.  For example, Mary is using CompuDance at the front desk and Jane is using it in the back office.  When Mary reads a record from a file, its contents are placed in her computer‘s memory.  When Jane reads the same record into her computer, it is also placed in memory on her computer.  If Mary changes the record and writes it to the file, and then Jane changes the record and writes her change to the file, her change is written over Mary’s change.  Or assume that while Jane is looking at the contents of the file, Mary changes those contents.  The change will not be reflected on Jane’s screen because what is on her screen is what her computer memorized when it read the file before Mary changed it.

     Just think of the types of data updating Mary and Jane could be doing: changing classes, moving students from one class to another, globally posting charges, posting payments, printing statements, etc., etc.  The solution to all of this is for Mary’s computer to restrict access to the file until she is finished with it; or, to have only one computer capable of changing data files at a time.  That would ensure that when Jane reads the file it would reflect the changes made by Mary. 

THE NETWORK VERSION

     The network version of CompuDance (called CDWNT from now on) supports multi-user access as follows.

     File Sharing

     CompuDance will allow two (or more) computers to have access to the same year/location data simultaneously.  In the above case when Jane, on the second computer, tries to access the same data file that is open and being used by Mary on the first computer, CompuDance will display a message that the file is currently being used by another computer and that Jane should wait until that file becomes available.  When Mary has finished with the file, CompuDance will release the file so that Jane can then access it.  The Windows error message “Permission Denied” should no longer be triggered.

     CompuDance will not keep files open for extended periods of time as it does in the non-networking version.  When Mary is accessing data, files will remain open and restricted only long enough to access the data.  That should be a matter of less than a second in most cases, several seconds in a few cases.  So, Jane won’t have to wait long.  Only when Mary is in a student/family ledger, entering payments, charges, or adjustments will data files remain open longer.  This is to protect the integrity of the financial data and student/family balances.

     Read/Write Access

     When using CDWNT, only one computer can have write access at a time.  The other computer(s) can have only read access.  In other words, one user can update (change) information, and the other computer can look at information.  So, Mary and Jane must decide who will be able to change data and who will be able to only read data.  If Mary decides that she is going to enter payments, change classes, post charges, etc., then she will open CompuDance on her computer for read/write access, and Jane will open it on her computer for read access only.  If later that day, Mary wants Jane to be able to make changes, then they will both exit CompuDance.  Mary will open it on her computer for read access only and Jane will open it on her computer for read/write access.  Now Jane can update class/student/family/financial data and Mary can read information only.

     Read/write access is available to a user who is running CompuDance with a Level 2 PassWord.  Read only access is available to a user who is running CompuDance with a Level 1 PassWord.  So, Mary would open the program on her computer with a Level 2 PassWord; Jane would open it on her computer with a Level 1 PassWord.

     Non-Multi-User Operations

     There are many operations that are not supported by CDWNT.  In general, these are ones that make wholesale changes to all  student/family records, or which are very security sensitive, or which in some other way affect your entire data file population.  These operations must be performed by the non-network version.  These are tuition scale calculation, backup/restore, global tuition/charge operations, adding/deleting years and locations, massive statement printing, EFT/Credit Card operations, E-Mail, and Configuration functions.  Most of these are done infrequently, as opposed to continuously throughout the day, day after day.

HOW TO INSTALL THE NETWORK VERSION

     NOTE:  You must install the non-network Version 8 of CompuDance before installing CDWNT!  Also, you must install 	   CDWNT on all network computers that you want to share data.

     Step 1  Place the CompuDance Distribution Disc in your CD-ROM drive.  Do not allow the auto run to start.  If it does,
                 click the <Cancel> button.

     Step 2  Double-click the My Computer icon on your Windows Desktop.

     Step 3  Double-click your CD-ROM Drive icon.

     Step 4  You will see a file named SETUP5.EXE.  Double-click it.

     Step 5  The SETUP Program will lead you through the installation process.

	1. A Dialog Box will prompt you to select a destination directory on your hard drive into which SETUP will
                 install CDWNT.  The suggested default directory is c:\Program Files\CDW (assuming that "c" is your hard drive).
                 You should accept the default!  All components of CompuDance must be installed in the same directory!

	2. SETUP will create backup copies of all files on your computer that are replaced during installation.  These are
                 Windows system files.

	3. SETUP will install CDWNT and display the file names while it installs.  The process is fast.   That’s it!
HOW TO RUN THE NETWORK VERSION 

The installation program will place a CompuDance NT icon on your Desktop and in the CompuDance 700 Program Group in your Start Menu.  The icon is handshaking to distinguish the CDWNT version from the regular version.

     Step 1  Double-click the icon.

     Step 2  You will be asked to enter your Password.  If you want to have write access, then enter your Level 2 Password.  If
                 you only need read access, and then enter your Level 1 Password.  Remember, only one computer can have write
                 access at a time.

	Do NOT run both the network version and the non-network version at the same time on a computer!!

HOW TO SET A PATH TO YOUR DATA FILES
     
     In order for more than one computer on a network to be able to access a common set of data files, each computer must know where those data files are located.  Are they on Computer A, Computer B, a server, the slave machine, etc., etc.?  Here is how you set the path to your data files so that each computer can find them.

     Step 1  Double-click My Computer.

     Step 2  In My Computer, double-click your Local Disk (C:). 

     Step 3 Double-click the Windows folder.  Scroll down until you find a file named CDWStud.ini.  Open it by double-clicking
	it’s icon.

     Step 4  You are now in the CompuDance .ini file.  The name of your studio should be in the second line.  Scroll down until
	you find an item named ProgPath=.  This is the CompuDance Program Path.  The default is c:\ProgramFiles\CDW.

     Step 5 Change the program path from the default to point to the location of your CompuDance data files.

     Step 6  When you are done, click File on the Menu Bar. Click Exit, then click Yes to save the changed file.

	Repeat these steps on each computer that will share CompuDance data files. 	 

Warning!
Be very careful when editing this .ini file.  It might be a good idea to make a copy before opening it.

NOTES

The following are known issues that users have reported in the past.

1. If you get a “Permission Denied” error, please write down what both computers were doing when the message occurred, and on which computer it appeared (the read/write computer or the read only computer).  Call us or send a Support Form from the web site.

2. If the “please wait” message appears, and the user waits for a little while, then clicks the Ok button to try to access the file again, and the message appears again, and this goes on for an unreasonable period of time, the user should verbally check with the other user to see what she/he is doing.  If she/he were taking a long time entering a payment, then that would be an explanation.  If, however, he/she has long finished entering a payment (or charge or adjustment) and is now just displaying an SRD or a FRD, please write down what both computers were doing when the message occurred, and on which computer it appeared (the read/write computer or the read only computer).  Call us or send a Support Form from the web site.  The “please wait” message should not keep coming back.

3. Sometimes you may get an error message as follows "File must not be open . . . ."  After the word “open” there will be some specific words identifying the exact location in the source code where that message was triggered.  Here are two examples:
 “in LoadClasses frmLists"  or  “in lstView1_DblClick frmAR” etc.  Please write down what both computers were doing when the message occurred, and on which computer it appeared (the read/write computer or the read only computer).  Call us or send a Support Form from the web site.

4. When you are entering a payment, or a charge, or an adjustment, or when you are displaying a student/family Ledger make certain the correct name of the student or family is in the title bar of the payment window, or charge window, or ledger window, or adjustment window.  If it contains the name of another student/family, please write down on which computer it appeared (the read/write computer or the read only computer).  Call us or send a Support Form from the web site.

5. When you are deleting a student, make certain that when it asks you if you are certain you want to delete this student/family, it displays the correct name.  Also, check carefully when adding classes to a student’s schedule and adding students to a family.  If there is a discrepancy, please call us or send a Support Form from the web site.

6. When a student/family ledger is displayed, make certain that both charges and payments are listed.  If only charges are there, please write down on which computer the problem exists (the read/write computer or the read only computer).  Call us or send a Support Form from the web site.

7. Because some features in the non-network Version 8 are not contained in CDWNT, you should only use CDWNT when two or more computers must have access to your data files simultaneously.  Otherwise, use the non-network version.    

8. You do not have to have the Level 1 and Level 2 passwords the same on both computers.  For example, the Level 1 Password on Computer A may be [jump], while the Level 1 Password on Computer B may be [skip].  Passwords are specific to each computer.

NOTE:  Please read the latest Readme File to confirm that the Network Version is compatible with Version 8.  You can also find that information on the Keeping In Touch page of our web site.  As of the printing of this Manual (March 2008) there was no Network Version 8 in BETA form.