IE8 error - "Object doesn't support this property or method"

Message: Object doesn’t support this property or method
Line: 201
Char: 1
Code: 0
URI: http://www.ics-software.co.uk/assets/snippets/ajaxSearch/js/ajaxSearch.js

Getting above error on client’s PC with ie8. Modx is installed on windows server. Anyone know a fix for this? Not sure if the search actually works - not been able to clarify this yet.

...maybe a workaround:

<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7" />

within your head-tags

http://ie8troubleshoot.blogspot.com/2010/07/object-doesnt-support-this-property-or.html