function showBox1(){
  document.getElementById('viiv').style.display='block';
  showTopBot(1);
}
function closeBox1(){
  document.getElementById('viiv').style.display='none';
  hideTopBot(1);
}
function showBox2(){
  document.getElementById('netzwerk').style.display='block';
  showTopBot(2);
}
function closeBox2(){
  document.getElementById('netzwerk').style.display='none';
  hideTopBot(2);
}
function showTopBot(i){
  document.getElementById('foot_top'+i).style.display='block';
  document.getElementById('foot_bot'+i).style.display='block';
}
function hideTopBot(i){
  document.getElementById('foot_top'+i).style.display='none';
  document.getElementById('foot_bot'+i).style.display='none';
}