Error Code in IE8

[fish4carp]

Hi All

I get this error code with IE8 any ideas as to why.

Error is below.

Message: Not implemented

Line: 94
Char: 4
Code: 0
URI: http://carpexperience.com/media/system/js/modal.js

Message: Object doesn't support this property or method
Line: 59
Char: 102
Code: 0
URI: http://carpexperience.com/media/system/js/mootools.js