var Resize = function(){
  // Groesse von ContentContainerMain ermitteln und ggf einstellen
  var CONTENT_height = document.getElementById("Content").offsetHeight;
  var LEFT_height = document.getElementById("Left").offsetHeight;
  var MENU_height = document.getElementById("MainMenu").offsetHeight;
  var IMAGE_height = document.getElementById("MenuImage").offsetHeight;
  
  if ( MENU_height > 310 ) {
    document.getElementById("Left").style.height =  LEFT_height + (MENU_height-310) + "px";
    var LEFT_height = document.getElementById("Left").offsetHeight;
  }  

  if ( CONTENT_height > LEFT_height ) {
    document.getElementById("Left").style.height =  CONTENT_height + "px";
  } else {
    document.getElementById("Content").style.height =  LEFT_height + "px";
  }
}