Empt=new Array(0,0,0,0);
var pcpos;
var geldig = true;
FieldName=new Array("Uw naam","Uw E-mail adres","E-mail adres collega")

function ValidTaf()
{
	if(document.getElementById('txtYourname').value.length<2)         Empt[0]=1
  if(!checkMail(document.getElementById('txtYouremail').value))     Empt[1]=1
  if(!checkMail(document.getElementById('txtFriendemail').value))   Empt[2]=1
  inv=0
  for(x=0;x<4;x++) 
  {
    if(Empt[x]==1) inv=1
  }
	(inv==0)	?	disable()	:	InVald()
}
	
function InVald()
{
	cntnt="U heeft 1 of meerdere velden niet volledig ingevuld:\n\n"
  	for(k=0;k<4;k++){
      if(Empt[k]==1)cntnt+="* "+FieldName[k]+"\n"
      Empt[k]=0
    }
  cntnt+="\nKlik OK om door te gaan."
  alert(cntnt)
  return
}

function checkMail(formelement)
{
  var syntaxvalid= false	
	var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,6})+$/;
	if (filter.test(formelement)) syntaxvalid = true;
	return syntaxvalid
}

function disable()
{
  document.getElementById('btnTellafriend').value="bezig met verzenden... momentje graag";
	document.getElementById('btnTellafriend').disabled=true;
	//DoAjax("frmTellafriend","http://amsterdamevents.nl/lib/global_tellafriend.php","ajaxcontainer","post");
	//document.frmTellafriend.method='post'
	//document.frmTellafriend.action='http://www.amsterdamevents.nl/lib/global_form_evaluatie.php';
	document.frmTellafriend.submit();
}