Added support for live re-auth and de-auth; fully AJAX, no page reload required, plus plugin-usable API.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>{#xhtmlxtras_dlg.title_del_element}</title>
<script type="text/javascript" src="../../tiny_mce_popup.js"></script>
<script type="text/javascript" src="../../utils/mctabs.js"></script>
<script type="text/javascript" src="../../utils/form_utils.js"></script>
<script type="text/javascript" src="../../utils/editable_selects.js"></script>
<script type="text/javascript" src="js/element_common.js"></script>
<script type="text/javascript" src="js/del.js"></script>
<link rel="stylesheet" type="text/css" href="css/popup.css" />
<base target="_self" />
</head>
<body id="xhtmlxtrasins" style="display: none">
<form onsubmit="insertDel();return false;" action="#">
<div class="tabs">
<ul>
<li id="general_tab" class="current"><span><a href="javascript:mcTabs.displayTab('general_tab','general_panel');" onmousedown="return false;">{#xhtmlxtras_dlg.general_tab}</a></span></li>
<!-- <li id="events_tab"><span><a href="javascript:mcTabs.displayTab('events_tab','events_panel');" onmousedown="return false;">{#xhtmlxtras_dlg.events_tab}</a></span></li> -->
</ul>
</div>
<div class="panel_wrapper">
<div id="general_panel" class="panel current">
<fieldset>
<legend>{#xhtmlxtras_dlg.fieldset_general_tab}</legend>
<table border="0" cellpadding="0" cellspacing="4">
<tr>
<td class="label"><label id="datetimelabel" for="datetime">{#xhtmlxtras_dlg.attribute_label_datetime}</label>:</td>
<td>
<table border="0" cellspacing="0" cellpadding="0">
<tr>
<td><input id="datetime" name="datetime" type="text" value="" maxlength="19" class="field mceFocus" /></td>
<td><a href="javascript:insertDateTime('datetime');" onmousedown="return false;" class="browse"><span class="datetime" alt="{#xhtmlxtras_dlg.insert_date}" title="{#xhtmlxtras_dlg.insert_date}"></span></a></td>
</tr>
</table>
</td>
</tr>
<tr>
<td class="label"><label id="citelabel" for="cite">{#xhtmlxtras_dlg.attribute_label_cite}</label>:</td>
<td><input id="cite" name="cite" type="text" value="" class="field" /></td>
</tr>
</table>
</fieldset>
<fieldset>
<legend>{#xhtmlxtras_dlg.fieldset_attrib_tab}</legend>
<table border="0" cellpadding="0" cellspacing="4">
<tr>
<td class="label"><label id="titlelabel" for="title">{#xhtmlxtras_dlg.attribute_label_title}</label>:</td>
<td><input id="title" name="title" type="text" value="" class="field" /></td>
</tr>
<tr>
<td class="label"><label id="idlabel" for="id">{#xhtmlxtras_dlg.attribute_label_id}</label>:</td>
<td><input id="id" name="id" type="text" value="" class="field" /></td>
</tr>
<tr>
<td class="label"><label id="classlabel" for="class">{#xhtmlxtras_dlg.attribute_label_class}</label>:</td>
<td>
<select id="class" name="class" class="field mceEditableSelect">
<option value="">{#not_set}</option>
</select>
</td>
</tr>
<tr>
<td class="label"><label id="stylelabel" for="class">{#xhtmlxtras_dlg.attribute_label_style}</label>:</td>
<td><input id="style" name="style" type="text" value="" class="field" /></td>
</tr>
<tr>
<td class="label"><label id="dirlabel" for="dir">{#xhtmlxtras_dlg.attribute_label_langdir}</label>:</td>
<td>
<select id="dir" name="dir" class="field">
<option value="">{#not_set}</option>
<option value="ltr">{#xhtmlxtras_dlg.attribute_option_ltr}</option>
<option value="rtl">{#xhtmlxtras_dlg.attribute_option_rtl}</option>
</select>
</td>
</tr>
<tr>
<td class="label"><label id="langlabel" for="lang">{#xhtmlxtras_dlg.attribute_label_langcode}</label>:</td>
<td>
<input id="lang" name="lang" type="text" value="" class="field" />
</td>
</tr>
</table>
</fieldset>
</div>
<div id="events_panel" class="panel">
<fieldset>
<legend>{#xhtmlxtras_dlg.fieldset_events_tab}</legend>
<table border="0" cellpadding="0" cellspacing="4">
<tr>
<td class="label"><label for="onfocus">onfocus</label>:</td>
<td><input id="onfocus" name="onfocus" type="text" value="" class="field" /></td>
</tr>
<tr>
<td class="label"><label for="onblur">onblur</label>:</td>
<td><input id="onblur" name="onblur" type="text" value="" class="field" /></td>
</tr>
<tr>
<td class="label"><label for="onclick">onclick</label>:</td>
<td><input id="onclick" name="onclick" type="text" value="" class="field" /></td>
</tr>
<tr>
<td class="label"><label for="ondblclick">ondblclick</label>:</td>
<td><input id="ondblclick" name="ondblclick" type="text" value="" class="field" /></td>
</tr>
<tr>
<td class="label"><label for="onmousedown">onmousedown</label>:</td>
<td><input id="onmousedown" name="onmousedown" type="text" value="" class="field" /></td>
</tr>
<tr>
<td class="label"><label for="onmouseup">onmouseup</label>:</td>
<td><input id="onmouseup" name="onmouseup" type="text" value="" class="field" /></td>
</tr>
<tr>
<td class="label"><label for="onmouseover">onmouseover</label>:</td>
<td><input id="onmouseover" name="onmouseover" type="text" value="" class="field" /></td>
</tr>
<tr>
<td class="label"><label for="onmousemove">onmousemove</label>:</td>
<td><input id="onmousemove" name="onmousemove" type="text" value="" class="field" /></td>
</tr>
<tr>
<td class="label"><label for="onmouseout">onmouseout</label>:</td>
<td><input id="onmouseout" name="onmouseout" type="text" value="" class="field" /></td>
</tr>
<tr>
<td class="label"><label for="onkeypress">onkeypress</label>:</td>
<td><input id="onkeypress" name="onkeypress" type="text" value="" class="field" /></td>
</tr>
<tr>
<td class="label"><label for="onkeydown">onkeydown</label>:</td>
<td><input id="onkeydown" name="onkeydown" type="text" value="" class="field" /></td>
</tr>
<tr>
<td class="label"><label for="onkeyup">onkeyup</label>:</td>
<td><input id="onkeyup" name="onkeyup" type="text" value="" class="field" /></td>
</tr>
</table>
</fieldset>
</div>
</div>
<div class="mceActionPanel">
<div style="float: left">
<input type="submit" id="insert" name="insert" value="{#update}" />
</div>
<div style="float: left">
<input type="button" id="remove" name="remove" class="button" value="{#xhtmlxtras_dlg.remove}" onclick="removeDel();" style="display: none;" />
</div>
<div style="float: right">
<input type="button" id="cancel" name="cancel" value="{#cancel}" onclick="tinyMCEPopup.close();" />
</div>
</div>
</form>
</body>
</html>