Validations on Textbox

I am trying to implement validation on textboxes placed on a form using ISNull function. I placed the code in a procedure and calling it on the click event of a button but does not work. I want also want to check for numeric and character data. here is my code

IF ISNULL(thisform.text2.Value) then
MESSAGEBOX("Please enter customer name")
ENDIF

Use this code:

IF ISBLANK(thisform.text2.value)

MESSAGEBOX("please...")

RETURN .f. &&abort execution of rest of the code

ENDIF

I believe in your case you're looking for EMPTY() function which correctly works for every data type.

In other words:

if empty(thisform.myTextbox.value)

=messagebox(...)

endif

Ahsan Amin wrote:

I am trying to implement validation on textboxes placed on a form using ISNull function. I placed the code in a procedure and calling it on the click event of a button but does not work. I want also want to check for numeric and character data.

In the Valid of the textbox:

This code in Str2Exp:

This is an overkill for the question asked.

You can simply create xEmpty function, which would be

No question the function can convert character value into the requested type representation. My point is, that for the question asked, this function is not needed and in this particular expression is an overkill.

If the question is whether data is empty or null we can either use simple UDF or use

#define XEMPTY empty(m.tuVal) or Isnull(m.tuVal)

tuVal = thisform.txtTest.value

if XEMPTY

=messagebox(...)

endif

The Str2Exp function may come handy in other situations, no doubt.

BTW, in your function this line

CASE lcType = 'L' && Logical
luRetVal = IIF( NOT EMPTY( tcExp ), .T., .F. )

can be re-written to

luRetVal = not empty(tcExp)