Object dosen't support this property or method with showModalDialog


We’re trying to open Modal Window from Modal Window on button click which is inside update panel:
[sourcecode language=”csharp”]
protected void Button1_Click(object sender, EventArgs e)
ScriptManager.RegisterStartupScript(Button1, page.GetType(), "OpenModalDialog", "<script type=text/javascript>window.showModalDialog(‘http://www.gooogle.com, null, ‘dialogHeight:100px;dialogWidth:280px;status:no’); </script>", false);
But it was giving an error Object dosen’t support this property or method


Pls  check that pop-up blocker is not active. [Tools | Pop-Up Blocker|Turn-off Pop-up Blocker].