復制代碼 代碼如下:

<asp:TextBox runat="server" TextMode="MultiLine" CssClass="textbox"
Width="250"></asp:TextBox><br />
<ajaxToolkit:TextBoxWatermarkExtender runat="server"
TargetControlID="txtCCEmail" WatermarkText="sample1@yourcompany.com; sample2@yourcompany.com;"
WatermarkCssClass="watermarked">
</ajaxToolkit:TextBoxWatermarkExtender>