unit extension problem in IE

Hello
I have installed scheduler with unit ext into my cakephp project . the script work properly in Chrome and Firefox but does not in IE.
the error is : ‘key’ is null or not an object ( in dhtmlxscheduler_url.js file line :73)
It would be grate if someone can help me overcome it
( the sample page is in the address : wanted.ir/shirazdaricheh/admin/books )

Check that array of units for the unit view has not trailin “,” at the end. ( IE process such case differently from FF and Chrome, which can cause the issue )

It is fixed due to what you say.
Thank you Stanislav