I built an internet site on joomla which utilizes several libraries , one of these Mootools, I have no idea much relating to this, however i think Joomla includes a Mootool automatically after which modules you put in get their owen Mootools Version, or Library , I'm using IE8 (all of the work stations that'll be being able to access the Intranet site) and also the warning that came is:

Message: Object does not support this property or method Line: 53 Char: 97 ..............system/js/mootools.js

Message: Object does not support this property or method Line: 59 Char: 102 Code: ................system/js/mootools.js

Code about this lines beginning on 53

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