function validEmail(theEntry) {
  badEntry = false
  invalidChars = " /:,;"     
  if (theEntry == "") { 
    badEntry = true
  }
  for (i=0; i < 5; i++)  {
    badChar = invalidChars.charAt(i)
    if (theEntry.indexOf(badChar,0) > -1) {
      badEntry = true
    }
  }  
  atsignLoc = theEntry.indexOf("@",1)
  if (atsignLoc == -1) {
    badEntry = true
  }     
  if (theEntry.indexOf("@",atsignLoc+1) > -1) {
    badEntry = true
  }
  dotLoc = theEntry.indexOf(".",atsignLoc)
  if (dotLoc == -1) {
    badEntry = true
  }
  if (dotLoc+3 > theEntry.length) {
    badEntry = true
  }
  return badEntry
}

function ValidateForm(frm) {
  var oFocusItem = null; 
  var content = "";
  validity = true;
  if (frm.Contactpersoon.value == "") {
    content = content + "- Contactpersoon\n";
    validity = false;
  }
  if (frm.plaats.value == "") {
    content = content + "- Plaats\n";
    validity = false;
  }
  if (frm.telefoon.value == "") {
    content = content + "- Telefoon\n";
    validity = false;
  }
  if (validEmail(frm.email.value)) {
    content = content + "- E-mail\n";
    validity = false;
  }
   if (frm.opmerking.value == "") {
    content = content + "- Klacht\n";
    validity = false;
  } 
  
  if (content == ""){
    if (frm.Gewenste.options[frm.Gewenste.selectedIndex].value == "empty"){
      content = "selecteer uw gewenste item";
      validity = false;
    }
  } else {
    content = "Vul a.u.b. de volgende velden in:\n\n" + content;
  }
  if (! validity) alert(content);
  return validity;
}