Setting tabbar width as % causes error in IE8

I need to set the size of my tabbar so that it occupies 100% of the width but different heights depending on which tab is chosen. This works in FireFox but IE8 gives an ‘invalid argument’ error at line 134 in dhtmlxtabbar.js and doesn’t proceed.

Please can you tell me what I need to do to achieve this.


We need the complete demo to recreate the problem locally.