function validateForm()
{
var x=document.forms["pcform"]["postcode"].value
if (x==null || x=="postcode")
  {
  alert("Vul uw postcode in.");
  return false;
  }
  
  var x=document.forms["pcform"]["huisnummer"].value
if (x==null || x=="huisnummer")
  {
  alert("Vul uw huisnummer in.");
  return false;
  }
}
function validateForm2()
{
var x=document.forms["pcform2"]["postcode"].value
if (x==null || x=="postcode")
  {
  alert("Vul uw postcode in.");
  return false;
  }
  
  var x=document.forms["pcform2"]["huisnummer"].value
if (x==null || x=="huisnummer")
  {
  alert("Vul uw huisnummer in.");
  return false;
  }
}