function changeContent(el,cnt){
        el.innerHTML = cnt;
      }

      function show(el){
        el.style.display = "block";
      }

      function hide(el){
        el.style.display = "none";
      }

      function setBGPosition(el,x,y){
        el.style.backgroundPosition = x+" "+y;
      }

      function validateAGB(){
        if (document.agbForm.agb.checked == false) {
          alert('Bitte akkzeptieren Sie noch unsere AGB');
          return false;
        } else {
          return true;
        }
      }