ChronoForms v3 requires Joomla! 1.5
From Joomla! 1.5.18 there is an optional MooTools Upgrade Plugin that will enable the MooTools 1.2 library on your site. If you need the plug-in you should update your Joomla! installation to the latsest release, currently 1.5.23, as some earlier releases did not implement the plug-in correctly.
ChronoForms v4 form Joomla! 1.5 requires MooTools 1.2 and so will only run in Joomla! 1.5.18 or later with the MooTools upgrade plug-in enabled. If you run ChronoForm v4 you should update your Joomla! installation to the latsest release, currently 1.5.25, as some earlier releases did not implement the plug-in correctly.
ChronoForms v4 is also released for Joomla! 1.6/1.7/2.5 These releases require the MooTools 1.3/1.4 library installed as standard with Joomla!
Note: If you need to run ChronoForms v3 and need MooTools 1.2 in the front-end of your site then there is a hack for the MooTools Upgrade plug-in posted in the forums here that will enable the 1.2 library in the front-end only. However the ChronoForms validation code and some other features will not work with this version.
There's a fuller "How-to Document" here that includes fixed files that will let the front-end of ChronoForms work with MooTools 1.2.
ChronoForms technical support
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