function Fensterhoehe(){
 if (window.innerHeight){
  return window.innerHeight;
 }else if (document.body && document.body.offsetHeight){
  return document.body.offsetHeight;
 }else if (document.body.clientHeight ){
  return document.body.clientHeight ;
 }else if (document.documentElement.clientHeight){
  return document.documentElement.clientHeight;
 }else{
  return 0;
 }
}

function resize()
{
  var hoehe = Fensterhoehe();
  var hoehe1 = Fensterhoehe();
  document.getElementById('test2').style.minHeight = ""+ hoehe +"px";
  hoehe1 = hoehe1 - 163; //original 205
  document.getElementById('test').style.minHeight = ""+ hoehe1 +"px";
}