Animate css switch
===

Is there a way to animate this function?
so when it "expands" switches between the css it does this slowly/medium/fast.


    
        function changeCssClass(objDivID)
        {
            if(document.getElementById(objDivID).className=='normalSize')
            {
                document.getElementById(objDivID).className = 'expandedSize';
            }
            else
            {
                document.getElementById(objDivID).className = 'normalSize';
            }
        } 
