On Jul 2, 10:30 am, "Dave griffiths" <davegino...@nospam.hotmail.com>
wrote:

I would do this:

  If IsNumeric(txt2.Text) Then
      x = Integer.Parse(txt2.Text)
  Else
      x = 0
  End If

Or Even this:

   Dim x as Integer = 0
   Integer.TryParse(txt2.Text, x)

Thanks,

Seth Rowe

In the txt2_LostFocus event handler, you can change the assignment of "x" to:

  x = CInt(Val(txt2.Text))

although some programmers consider Val to be an unsafe alternative to actual
formal checking of the data. Also, there are some minor situations where
Val will generate an error instead of returning zero for unrecogized input.

-----
Tim Patrick - www.timaki.com
Start-to-Finish Visual Basic 2005

Well in a pinch you can use....
-------------------------------------------------------------
txt3.text = cint(iif(txt2.text = "", 0, txt2.text)) + y
-------------------------------------------------------------
... but at this point I would suggest that the proper way to do this would
be to create som sort of validation routine...

-------------------------------------------------------------
Public function ValidateForm(ErrorMessage as  String) as Boolean
-------------------------------------------------------------

My first reply seems to have mysteriously disappeared. so I will try again :)

Essentially I agree with Seth.

I would however suggest that for anything that might eventually be a less
than trivial form, that you should consider the creation of a function to
validate the form itself before proceeding to perform calculations based
on the data in that form.

for example
-------------------------------------------------------------
Public Function isFormValid(ByRef ErrorMessage as String) as Boolean
    If SomeBadCondition then
         ErrorMessage = "Alert User of Problem"
         Exit Sub
    End If
    If SomeOtherBadCondition then
         ErrorMessage = "Alert User of Problem2"
         Exit Sub
    End If

    Return True
End Function
-------------------------------------------------------------

Later on you can say...
-------------------------------------------------------------
Public Sub PerformCalculation
    ' check form first
    Dim TheErrorMessage as String
    If Not isFormValid(ThePotentialErrorMessage) then
         MessageBox.Show(TheErrorMessage)
         Exit Sub
    End If
    ' Now perform calculation
...
...
...
End Sub
-------------------------------------------------------------

This is probably overkill for any small calculation but on larger dataentry
forms, something like this can save you a lot of trouble.

--
Rory

Hi All

Thanks for so much input so quickly.

I agree with Rory that there needs to be some kind of form validation,
I was really asking the correct or should I say tidier way of
performing the conversion.

As the form uses extensive numeric textboxes I plan to create my own
class "numtext" with the information kindly supplied here to handle the
problem.