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:nCVI Function Programming Example
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CVI, CVS, CVL, and CVD Functions Programming Example
 
The following program illustrates the use of MKS$ and CVS. If you run
this program, you will be prompted to enter an "account #." The account
numbers in the sample data file ACCOUNT.INF are 1, 2, 3, 4, and 5.
 
After you enter an account number, the program gives you a chance to
update the account balance.
 
' *** Example program that uses the CVS function ***
'
' Define a user type for the data records.
TYPE Buffer
   AccName AS STRING * 25
   Check   AS STRING * 4
END TYPE
' Define a variable of the variable type
DIM BankBuffer AS Buffer
OPEN "ACCOUNT.INF" FOR RANDOM AS #1 LEN = 29
CLS
RESTORE
READ AccName$, Check
I = 0
DO WHILE UCASE$(AccName$) <> "END"
   I = I + 1
   BankBuffer.AccName = AccName$
   BankBuffer.Check = MKS$(Check)
   PUT #1, I, BankBuffer
   READ AccName$, Check$
   IF AccName$ = "END" THEN EXIT DO
LOOP
CLOSE #1
'
   DATA "Bob Hartzell", 300
   DATA "Alice Provan", 150
   DATA "Alex Landow", 75
   DATA "Walt Riley", 50
   DATA "Georgette Gump", 25
   DATA "END", 0
 
'*******************************************************************
OPEN "ACCOUNT.INF" FOR RANDOM AS #2 LEN = 29
FIELD #2, 25 AS AccName$, 4 AS Check$
 
Format$ = "$$#####.##"
DO
   PRINT
   DO
      INPUT "Enter account # to update: ", Rec%
      GET #2, Rec%                               'Get the record
      PRINT "This is the account for "; AccName$
      INPUT "Is this the account you wanted"; R$
   LOOP WHILE UCASE$(MID$(R$, 1, 1)) <> "Y"
 
   'Convert string to single-precision number.
   Checkamt! = CVS(Check$)
   PRINT
   PRINT "The opening balance for this account is";
   PRINT USING Format$; Checkamt!
   PRINT "Enter the checks and cash withdrawals for this"
   PRINT "account below. Enter 0 when finished."
 
   DO
      INPUT Checkout!
      Checkamt! = Checkamt! - Checkout!
   LOOP UNTIL Checkout! = 0
 
   PRINT
   PRINT "Enter the deposits for this account below."
   PRINT "Enter 0 when finished."
 
   DO
      INPUT Checkin!: Checkamt! = Checkamt! + Checkin!
   LOOP UNTIL Checkin! = 0
 
   PRINT
   PRINT "The closing balance for this account is";
   PRINT USING Format$; Checkamt!
   'Convert single-precision number to string.
   LSET Check$ = MKS$(Checkamt!)
   PUT #2, Rec%                                  'Store the record.
   INPUT "Update another"; R$
 
LOOP UNTIL UCASE$(MID$(R$, 1, 1)) <> "Y"
CLOSE #2
END