Question

I added a regex validator but its not showing anything on the page, basically the validation is done somewhere else i just needed to fire up. Here is the validator

    <div>
       <asp:RequiredFieldValidator 
        ID="RegularNoCardAccepted" runat="server"    
        ControlToValidate="txtCreditCardNumber" 
        CssClass="Error" Display="Dynamic">
        </asp:RequiredFieldValidator>
    </div> 

And here is how I am trying to fire up, in reality i dont need it to check against a regular expression, I am just not sure how to make it pop up when it meets this condition

  if (CardNotAccepted())
        {
  //Find the validator located somewhere in the master page.
  RequiredFieldValidator reqVal = 
  FindControlRecursive(this.Page.Master, "RegularNoCardAccepted") 
  as RequiredFieldValidator;

                    if (reqVal != null)
                    {
                        //The code goes through here but it never shows.
                        reqVal.Enabled = true;
                        reqVal.Text = "Credit Card Type is not accepted";
                        reqVal.Visible = true;
                        reqVal.Validate();
                    }
                    return;
                }

Answer 1

ASP.NET FieldValidators work automatically (assuming the Enabled property is set to true) on POST events. Here is an example of use: http://www.w3schools.com/aspnet/showasp.asp?filename=demo_reqfieldvalidator