Use CustomValidator To Validate Empty TextBoxes

Hi

try this Example to validate Empty textbox and change it border color

if it empty to Red

Step 1 : create new web site and add new page

Step2 : add two TextBoex and two CustomValidator controls and ValidationSummary control and a Button in your page

<script type=”text/javascript”>
    function vali(source, args)
    {
    if(document.getElementById(source.controltovalidate).value.length > 0)
      {
      args.IsValid = true;
      document.getElementById(source.controltovalidate).style.borderColor=’green’;
      }
     else
      {
      args.IsValid =false;
      document.getElementById(source.controltovalidate).style.borderColor=’red’;
      }
   
    }
</script>

<asp:TextBox ID=”TextBox1″ runat=”server”></asp:TextBox>
        <asp:CustomValidator ID=”CustomValidator1″ runat=”server” ControlToValidate=”TextBox1″
            ErrorMessage=”Enter First Name” SetFocusOnError=”True” ClientValidationFunction=”vali” ValidateEmptyText=”True” Display=”None”>Enter First Name</asp:CustomValidator><br />
        <asp:TextBox ID=”TextBox2″ runat=”server”></asp:TextBox>
        <asp:CustomValidator ID=”CustomValidator2″ runat=”server” ClientValidationFunction=”vali”
            ControlToValidate=”TextBox2″ Display=”None” ErrorMessage=”Enter Second Name”
            SetFocusOnError=”True” ValidateEmptyText=”True”>Enter Second Name</asp:CustomValidator><br />
        <br />
        <asp:ValidationSummary ID=”ValidationSummary1″ runat=”server” ShowMessageBox=”True”
            ShowSummary=”False” />
        <br />

        <asp:Button ID=”Button1″ runat=”server” Text=”Button” />

Hope this helps

Good Luck