Getting Textbox Watermark Text in client side javascript

This example is a modified version of the the Toolkit's TextBoxWatermark.aspx. The key is assigning a BehaviorID to the TextBoxWatermarkExtender and then you can locate it using $find.

<asp:Content ContentPlaceHolderID="SampleContent" Runat="Server"> <script> function compareText() { var tb = $get("<%=TextBox1.ClientID %>"); var behavior = $find("Extender1"); if(tb.value == behavior._watermarkText) { alert("Value has not changed!"); } else { alert("Value has changed!"); } } </script> <asp:ScriptManager EnablePartialRendering="true" runat="Server" /> <div class="demoarea"> <div class="demoheading">TextBoxWatermark Demonstration</div> <asp:UpdatePanel ID="UpdatePanel1" runat="server"> <ContentTemplate> First name: <button onclick="compareText()" value="aaa">aaa</button> <asp:TextBox ID="TextBox1" CssClass="unwatermarked" Width="150" runat="server" /><br /> <ajaxToolkit:TextBoxWatermarkExtender ID="TextBoxWatermarkExtender1" runat="server" TargetControlID="TextBox1" WatermarkText="Type First Name Here" WatermarkCssClass="watermarked" BehaviorID="Extender1" /> Last name: <asp:TextBox ID="TextBox2" CssClass="unwatermarked" Width="150" runat="server" /><br /><br /> <ajaxToolkit:TextBoxWatermarkExtender ID="TextBoxWatermarkExtender2" runat="server" TargetControlID="TextBox2" WatermarkText="Type Last Name Here" WatermarkCssClass="watermarked" /> <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Submit" /> <br /><br /> <asp:Label ID="Label1" runat="server" /> </ContentTemplate> </asp:UpdatePanel> </div> <div class="demobottom"></div>

Beautiful! Thanks for replying! I will give it a try!