function doResize(){
    var centerHeight = document.getElementById('center').offsetHeight;
   
    var leftHeight	= document.getElementById('left').offsetHeight;
    var rightHeight	= document.getElementById('right').offsetHeight;
    
    var arrayValori = new Array();
    arrayValori[0] = centerHeight;
    arrayValori[1] = leftHeight;
    arrayValori[2] = rightHeight;
    arrayOrdina = arrayValori.sort();
    arrayValori.sort(numberSorter);
    arrayValori.reverse();
    document.getElementById('right').style.height=arrayOrdina[0]+'px';
    document.getElementById('left').style.height=arrayOrdina[0]+'px';
    document.getElementById('center').style.height=arrayOrdina[0]+'px';
}
function numberSorter(a, b) {
	return a - b;
}