Hi go thr this

Public Sub TextBox1_Validating(ByVal sender As Object, _
      ByVal e As System.ComponentModel.CancelEventArgs) _
      Handles TextBox1.Validating

    try
    {
      int value=Int32.Parse(this.Text);
    }
    catch(Exception)
    {
      e.Cancel=true;
      MessageBox.Show("Please Enter Numeric Value");
    }

   OR Do like this;

int keyCode= Convert.ToInt16(e.KeyChar);

 if ((keyCode >= 97 && keyCode <= 122) || (keyCode == 8))

{

e.Handled = false;

}

else

{

e.Handled = true;

MessageBox.Show("Please Enter Numeric Value");

}

End Sub

Just go thr these links you will find it.

http://www.java2s.com/Code/VB/GUI/TextBoxValidatingEvent.htm

http://www.csharphelp.com/archives/archive64.html

http://www.csharphelp.com/archives/files/archive64/NumberBox.cs

Best Luck!!!!!!!!!!

Sujit.