window.onscroll = scroll;

function resize() {
  var window = document.documentElement.clientHeight;
  var header = (document.getElementById("header-wrapper").offsetHeight + 22);
  var body = window - header;
  var contentLeftTop = document.getElementById("content-left-top").offsetHeight;
  var contentLeftBottom = document.getElementById("content-left-bottom").offsetHeight;
  var contentLeftMiddle = (body - (contentLeftTop + contentLeftBottom) + document.documentElement.scrollTop);
  
  document.getElementById("content-left-middle").style.height = contentLeftMiddle + "px";
}

function scroll() {
  var window = document.documentElement.clientHeight;
  var header = (document.getElementById("header-wrapper").offsetHeight + 22);
  
  if(document.all) {
    var header = (document.getElementById("header-wrapper").offsetHeight + 44);
  }
  
  var body = window - header;
  var contentLeftTop = document.getElementById("content-left-top").offsetHeight;
  var contentLeftBottom = document.getElementById("content-left-bottom").offsetHeight;
  var contentLeftMiddle = (body - (contentLeftTop + contentLeftBottom) + document.documentElement.scrollTop);
  
  document.getElementById("content-left-middle").style.height = contentLeftMiddle + "px";
}