function openWindow(tpnumber)
{
  var kenteken1 = document.getElementById('kenteken1').value;
  var kenteken2 = document.getElementById('kenteken2').value;
  var kenteken3 = document.getElementById('kenteken3').value;
  
  var kenteken  = kenteken1+kenteken2+kenteken3; 
  var url       = 'https://www.poliscomfort.nl/portal/inloggen.aspx?tp='+tpnumber+'&showProduct=5&Kenteken='+kenteken;
  var popup     = window.open(url,'Popup','height=540,width=1055,scrollTo,resizable=0,scrollbars=1,location=0,left=50,top=50','false');
  
  //https%3A%2F%2Fwww.poliscomfort.nl%2Fportal%2Finloggen.aspx%3Ftp%3DAK3706%26showProduct%3D5%26Kenteken%3D+kenteken; 
  
  popup.focus();
}

function focusNext()
{
  var a = document.getElementById('kenteken1').value;
  var b = document.getElementById('kenteken2').value;
  var c = document.getElementById('kenteken3').value;
  if(a.length == 2 && b.length < 1) { document.getElementById('kenteken2').focus(); }
  if(b.length == 2) { document.getElementById('kenteken3').focus(); }
  if(c.length == 2) { document.getElementById('submit').focus(); }
}

function makeUpperCase(value)
{
  value.toUpperCase();
}