为TextBox装饰水印

<script type="text/javascript">
        var watermarkText = "输入名称";

        function WaterMarkOnBlur(textbox) {
            if (textbox.value.length == 0) {
                textbox.style.color = "gray";
                textbox.value = watermarkText;
            }            
        }

        function WaterMartOnfocus(textbox)
        {
            if (textbox.value == watermarkText) {
                textbox.style.color = "black";
                textbox.value = "";
            }
        }
    </script>

<asp:TextBox ID="TextBox1" runat="server" Text="输入名称"
2                 ForeColor="Gray" onblur="WaterMarkOnBlur(this);"
3                 onfocus="WaterMartOnfocus(this);">
4             </asp:TextBox>