function controleerBel(formulier)
{
   var melding = "";

	if(formulier.Naam.value == "")
   {
       document.getElementById("Naam").className = 'veldFout';
       if(melding == "") document.getElementById("Naam").focus();
       melding = "geef melding";
   }
   else
   {
       document.getElementById("Naam").className = 'veld';
   }
	 
	if(formulier.TelefoonNr.value == "")
   {
       document.getElementById("TelefoonNr").className = 'veldFout';
       if(melding == "") document.getElementById("TelefoonNr").focus();
       melding = "geef melding";
   }
   else
   {
       document.getElementById("TelefoonNr").className = 'veld';
   }

   if (melding !== "")
   {
       document.getElementById("Melding").style.display = 'block';
       return (false);
   }
}