if (window.addEventListener) {
window.addEventListener ("load", equal, false);
} else if (window.attachEvent) {
window.attachEvent ('on' + "load", equal);
}

function equal(){
var l = document.getElementById('leftColumn');
var r = document.getElementById('content');
var max = r.offsetHeight + 20;
l.style.height = max + 'px';
r.style.height = max + 'px';
}