function sloupce()
{
	max=0;
	if(document.getElementById('leftc').offsetHeight>max)
		max=document.getElementById('leftc').offsetHeight;
		
	if(document.getElementById('midc').offsetHeight>max)
		max=document.getElementById('midc').offsetHeight;
		
	if(document.getElementById('rightc').offsetHeight>max)
		max=document.getElementById('rightc').offsetHeight;
	
	document.getElementById('leftc').style.height=max+"px";
	document.getElementById('midc').style.height=max+"px";
	document.getElementById('rightc').style.height=max+"px";
	
}