function resizeContainer() { 

    var leftbar = document.getElementById("leftbar");
    var rightbar = document.getElementById("rightbar");
   
    var rightbarheight = 0;
    
    // set content height to actual height of content.
    if (rightbar.offsetHeight) { rightbarheight = rightbar.offsetHeight; } 
        else if(rightbar.style.pixelHeight){ rightbarheight=rightbar.style.pixelHeight; } 
  
    leftbar.style.height = (rightbarheight) + "px"; // take 20 for margins.    

}