Problem in hiding panel

 hi all
i am using a checkbox to hide and show a few panels
the problem is that it works fine in internet explorer 7
but not in firefox
instead of hiding two panels get superimposed over each other
but still is perfect in ie
I am having similar problem with Ajax collapsible panel. there the collapsing and expanding work fine in firefox and opera but not in ie
what do i do?

 
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