Set Content-type on AJAX login key request to application/json to hopefully block ad injection
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>{$lang_theme_charmap_title}</title>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />
<script language="javascript" type="text/javascript" src="../../tiny_mce_popup.js"></script>
<script language="javascript" type="text/javascript" src="jscripts/charmap.js"></script>
<base target="_self" />
</head>
<body onload="tinyMCEPopup.executeOnLoad('init();');" style="display: none">
<table align="center" border="0" cellspacing="0" cellpadding="2">
<tr>
<td colspan="2" class="title">{$lang_theme_charmap_title}</td>
</tr>
<tr>
<td rowspan="2" align="left" valign="top">
<script language="javascript" type="text/javascript">renderCharMapHTML();</script>
</td>
<td width="100" align="center" valign="top">
<table border="0" cellpadding="0" cellspacing="0" width="100" style="height: 100px">
<tr>
<td class="charmapOver" style="font-size: 40px; height:80px;" id="codeV"> </td>
</tr>
<tr>
<td style="font-size: 10px; font-family: Arial, Helvetica, sans-serif; text-align:center;" id="codeN"> </td>
</tr>
</table>
</td>
</tr>
<tr>
<td valign="bottom" style="padding-bottom: 3px;">
<table width="100" align="center" border="0" cellpadding="2" cellspacing="0">
<tr>
<td align="center" style="border-left: 1px solid #666699; border-top: 1px solid #666699; border-right: 1px solid #666699;">HTML-Code</td>
</tr>
<tr>
<td style="font-size: 16px; font-weight: bold; border-left: 1px solid #666699; border-bottom: 1px solid #666699; border-right: 1px solid #666699;" id="codeA" align="center"> </td>
</tr>
<tr>
<td style="font-size: 1px;"> </td>
</tr>
<tr>
<td align="center" style="border-left: 1px solid #666699; border-top: 1px solid #666699; border-right: 1px solid #666699;">NUM-Code</td>
</tr>
<tr>
<td style="font-size: 16px; font-weight: bold; border-left: 1px solid #666699; border-bottom: 1px solid #666699; border-right: 1px solid #666699;" id="codeB" align="center"> </td>
</tr>
</table>
</td>
</tr>
</table>
</body>
</html>