Determine if aspx page was opened by a window.open() command
<p>Is there a way to determine in the child page's code behind that is was opened by the window.open() javascript command from the parent page?</p>

<p>The pop-up page contains a user control that is used by other pages that are not spawned from a window.open() command and I want to dynamically add functionality to close the page after the user has completed their task in the child page.</p>

<p>It is an ASP.NET C# 3.5 application. </p>
