Mega Code Archive
RequiredFieldValidator requires a user to enter a value into a form field before submitting the form
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Two important properties when using the RequiredFieldValdiator control:
ControlToValidate: The ID of the form field being validated.
Text: The error message.
<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Show RequiredFieldValidator</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Label
id="lblFirstName"
Text="First Name:"
AssociatedControlID="txtFirstName"
Runat="server" />
<asp:TextBox
id="txtFirstName"
Runat="server" />
<asp:RequiredFieldValidator
id="reqFirstName"
ControlToValidate="txtFirstName"
Text="(Required)"
Runat="server" />
<asp:Label
id="lblLastName"
Text="Last Name:"
AssociatedControlID="txtLastName"
Runat="server" />
<br />
<asp:TextBox
id="txtLastName"
Runat="server" />
<asp:RequiredFieldValidator
id="reqLastName"
ControlToValidate="txtLastName"
Text="(Required)"
Runat="server" />
<asp:Button
id="btnSubmit"
Text="Submit"
Runat="server" />
</div>
</form>
</body>
</html>
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