>>>Actually I was just trying this code and keep getting "Operator/operand type mistmatch":
>>>
>>>

proIn = 61227660  &&RLCA
>>>
>>>lnDigit = m.proIn - (INT(m.proIn / 9) * 9)
>>>		chkdig = 9 - lnDigit
>>>		
>>>??proIn + chkdig+CHR(13)+CHR(10)

>>>
>>>It must have something to do with the proIn field because the chkdig is generated fine by itself.
>>
>>You are combining numerics and characters (CHR()) in the last line of your code
>>
>>Regards,
>>Pieter
>
>Ok, at first I thought I was getting the same error when I actually tried running the page instead of just the code, but I see they're different.
>
>When I run the server and actually try to use my page I created for this code, I get this error:
>
>Error Number: 9
>Error: Data type mismatch.
>
>The actual code:
>
>

>FUNCTION ReturnChkDig( ProIn, ValidNo )
>ProIn = ALLTRIM(ProIn)
>CASE validNo = 12 && RLCA
>		lnDigit = m.proIn - (INT(m.proIn / 9) * 9)
>		chkdig = (INT(9 - lnDigit))
>
>OTHERWISE
>		chkdig = " "
>				
>	ENDCASE  
>		RETURN TRANSFORM(chkdig)
>ENDFUNC
>

>
>There are multiple cases, but this is the only one not working.

You can not change type of the expression in the case statement. In the top chkdig is numeric and in the second statement it's character. It should be either character in both or numeric in both.