Validating numeric textbox in vb net
If this value is greater than 0 then it says it's not valid. Index Of(".") This should restrict user input to decimal values, allowing negative values as well. I am trying to set up a form to accept a telephone number, but i am unsure of how to validate it so it will only take numeric values with 11 digits. Show("You must enter a Telephone Number.", "Data Entry Error", Message Box Buttons. Information) 'makes sure that only numbers and the backspace are allowed in the fields. It can contain only unformatted text in its Text property. In many situations you need to enter only numeric values in the Textbox.