function checkForm() 
 {
  var form = document.kontakt;

  if(form.name.value == "") 
  {
   alert('Geben Sie bitte Ihren Namen an!');
   form.name.focus();
   return false;
  }

  if(!form.email.value.match(/^[a-zA-Z0-9_\.-]{2,}@[a-zA-Z0-9-]{3,}\.[a-zA-Z]{2,4}$/i) && !form.tel.value.match(/^[0-9]{3,}$/))
  {
   alert('Geben Sie bitte eine gültige E-Mail-Adresse oder eine Telefonnummer an.\n\n(Bitte nur Ziffern als Telefonnummer verwenden!)');
   form.email.focus();
   return false;
  } 
  
  if(form.kommentar.value == "") 
  {
   alert('Ihre Anfrage?');
   form.kommentar.focus();
   return false;
  }            
 }
 
 
 function Show(url, width, height) 
 {
  var winname;
  winname = window.open(url,"",'width=' + width + ',height=' + height + ',resizable=0,scrollbars=no,menubar=no,status=no,resizable=no' );
  winname.moveTo((screen.width-width)/2,(screen.height-height)/2); 
 }
 
 function show(divid) 
 {   
  d=document; 
  d.getElementById(divid).style.display="inline"; 
 } 
  
 function hide(divid) 
 {   
  d=document; 
  d.getElementById(divid).style.display="none"; 
 } 
 
 function name_form_image(form,divid,divid2)
 {
  var f = document.getElementById(divid).value;
  var n = f.split("\\");
  n.reverse();
  var s = n[0].split(".");
  var x = s[0];
  var z = document.getElementById(divid2).value = x;  
 }