C$PROGINSTACK
This routine determines whether a COBOL program is already present in the current CALL stack.
Syntax:
 CALL "C$PROGINSTACK" USING progName 
                     GIVING returnCode
Parameters:
progName
PIC X(n)
Specifies the program to check.
Return code:
returnCode can be any signed numeric data item and provides additional information:
-1
wrong parameters.
0
program not in the stack.
1
program found in the stack.
Examples:
Example - Check if a program is in the current CALL stack
call "c$proginstack" using "computetax"
if return-code not = 1
   display message "ComputeTax is not in the stack"
end-if