代码如下：
<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
void Page_Load()
{
txtFirstName.Focus();
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head >
<title>TextBox Focus</title>
</head>
<body>
<form >
<div>
<asp:Label
Text="First Name:"
AssociatedControlID="txtFirstName"
Runat="server" />
<br />
<asp:TextBox
AutoCompleteType="FirstName"
Runat="server" />
<br /><br />
<asp:Label
Text="Last Name:"
AssociatedControlID="txtLastName"
Runat="server" />
<br />
<asp:TextBox
AutoCompleteType="LastName"
Runat="server" />
<br /><br />
<asp:Button
Text="Submit"
Runat="server" />
</div>
</form>
</body>
</html>
运行后，光标出现在txtFirstName的文本输入控件里。