function get_page_height(){
  var schHei;
  
  scnHei = document.getElementById('logo_bar').offsetHeight;
  if (document.getElementById('contentDiv').offsetHeight > scnHei){
    scnHei = document.getElementById('contentDiv').offsetHeight;
  }
  else{
    document.getElementById('contentDiv').style.height = scnHei
  }
  document.getElementById('mainDiv').style.height = scnHei + 350;
  //alert(document.getElementById('contentDiv').offsetHeight);
}