var $$ = function(id) {
  return document.getElementById(id);
};


function checkHeight() {
  var left = $$('left');
  var center = $$('center');
  var right = $$('right');

  if (left && center && right) {
    var hArr = new Array(left.offsetHeight, center.offsetHeight, right.offsetHeight);
    var theHighest = 0;
    for (var i = 0; i < hArr.length; i++) {
      if (hArr[i] > theHighest) theHighest = hArr[i];
    }
    left.style.height = theHighest + "px";
    center.style.height = theHighest + "px";
    right.style.height = theHighest + "px";

  }
}