Show Processing message on actions in ASP.Net

function Wait()
{
$get('ctl00_ContentPlaceHolder1_UpdateProgress2').style.display = 'block';
var div = document.getElementById('progressBar');
div.style.visibility='visible';
document.getElementById('progressBar').innerHTML='<img src=Progressbar.gif><font size=2>Processing, Please Wait...</font>';
}

On aspx page

<asp:Button ID="btnSearch" OnClick="btnSearch_Click" runat="server" Text="Search"
OnClientClick="javascript: Wait();"></asp:Button>

<asp:UpdateProgress ID="UpdateProgress2" AssociatedUpdatePanelID="uPnlSearch" runat="server">
<ProgressTemplate>
<div style="visibility: hidden" id="progressBar">
<font style="color: #000000" color="#336633" size="2">Processing, Please Wait...</font>
<img src=" Progressbar.gif" />
</div>
</ProgressTemplate>
</asp:UpdateProgress>