How to check if a POST submitted field exists in VBScript?

Question

After a form is submitted, how does one check server-side if a particular field exists? For example:

If [Exists] Request(\"FieldName\") Then
    ...
End If
<         


        

Answer 1

I usually check the value of the SUBMIT button. If it was clicked, it's value is posted along with the form data. So, even if all your form data is blank, the submit button's value will not be. And if the submit button's value is blank, then it wasn't clicked.

if request("btn_Submit") <> "" Then
    response.write "form was submitted"
end if

This is more difficult if you are using a javascript form.submit() call, in which case I usually opt for the hidden field.