<script language="JavaScript"><!--
function open_popup(page) {
    window.open(page);
    return false;
}

open_popup('page1.htm');
//--></script>

<p>
<a href="page2.htm" onClick="return open_popup('page2.htm')">Open Popup</a>
</p>

<form action="page3.htm">
<input type="submit" onClick="return open_popup('page3.htm')" value="Open Pop-up">
</form>