asp button onclick reloads the parent page
<p>I have a button and added onlcik event from the code behind. When I click on the button it reloads the parent page. What could be the problem? Please let me know.</p>

<pre><code>&lt;asp:Button ID="btnReport" runat="server" Text="Report"/&gt;
</code></pre>

<p>Code behind:</p>

<pre><code>string url = "http://www.google.com";

Page.ClientScript.RegisterStartupScript(this.GetType(), "OpenWin", 
    "&lt;script language=javascript&gt;function Report() { window.open ('" + 
    url + "', null,'top=1,left=1,center=yes,resizable=no,Width=840px,
    Height= 300px,status=no,titlebar=no;toolbar=no,
    menubar=no,location=no,scrollbars=yes');}&lt;/script&gt;");

btnReport.Attributes.Add("OnClick", "Report()");
</code></pre>
