function CheckForm(form) {
  submit=true;
  form= document.forms[form];
  for (i=0;i<form.elements.length;i++)
  {
    if (form.elements[i].type == "text" && form.elements[i].value=="")
    {
      alert("Du hast dieses Feld vergessen: " + form.elements[i].name);
      i=8;
      submit=false;
    }
  }  
  if (submit) { form.submit(); }
}