ValidatorCalloutExtender

<%@ Page Language="C#" MasterPageFile="~/Default.master" Title="Untitled Page" %>


<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
    <style>
    .highlight {
        background-color: Yellow;
    }
</style>
    
    
   <asp:Label ID="lbl" runat="server" Text="请输入Email地址:"/> <asp:TextBox ID="tbEmail" runat="server" CssClass="highlight"/>
    <asp:RegularExpressionValidator ID="emailValidator" runat="server" ControlToValidate="tbEmail" Display="none" ErrorMessage="Please input a valid Email Address." ValidationExpression="\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*"/>
   <ajaxToolkit:ValidatorCalloutExtender ID ="vce" runat="server" TargetControlID="emailValidator" Width ="200px" HighlightCssClass="hightlight"  WarningIconImageUrl="~/Images/warning.png"  />
    


</asp:Content>