function checkForm()
{
	var naam = document.getElementById('naam');
	var email = document.getElementById('email');
	var vraag = document.getElementById('vraag');
	
	if(naam.value == '') { alert('U heeft geen naam ingevuld.'); return false; }
	else if(email.value == '') { alert('U heeft geen e-mailadres ingevuld'); return false; }
	else if(vraag.value == '') { alert('U heeft geen vraag ingevuld.'); return false; }
	else { return true; }
}

 function wopen(url,wname,flags,w,h) {
    var par='';
    var left = Math.floor( (screen.width - w) / 2);
    var top = Math.floor( (screen.height - h) / 2);
    if(flags&1)  { par+='scrollbars=1,';  } else { par+='scrollbars=0,';  }
    if(flags&2)  { par+='status=1,';      } else { par+='status=0,';      }
    if(flags&4)  { par+='resizable=1,';   } else { par+='resizable=0,';   }
    if(flags&8)  { par+='toolbar=1,';     } else { par+='toolbar=0,';     }
    if(flags&16) { par+='location=1,';    } else { par+='location=0,';    }
    if(flags&32) { par+='menubar=1,';     } else { par+='menubar=0,';     }
    if(flags&64) { par+='directories=1,'; } else { par+='directories=0,'; }
    //alert(par);
    win  = window.open(url,wname,'width=' + w + ', height=' + h + ',' + par + 'top=' + top + ',left=' + left);
    win.focus();
  }

 function wopen2(url,wname,flags,w,h) {
    var par='';
    var left = Math.floor( (screen.width - w) / 2);
    var top = Math.floor( (screen.height - h) / 2);
    if(flags&1)  { par+='scrollbars=1,';  } else { par+='scrollbars=0,';  }
    if(flags&2)  { par+='status=1,';      } else { par+='status=0,';      }
    if(flags&4)  { par+='resizable=1,';   } else { par+='resizable=0,';   }
    if(flags&8)  { par+='toolbar=1,';     } else { par+='toolbar=0,';     }
    if(flags&16) { par+='location=1,';    } else { par+='location=0,';    }
    if(flags&32) { par+='menubar=1,';     } else { par+='menubar=0,';     }
    if(flags&64) { par+='directories=1,'; } else { par+='directories=0,'; }
    //alert(par);
    win  = window.open(url,wname,'width=' + w + ', height=' + h + ',' + par + 'top=' + top + ',left=' + left);
    win.focus();
  }
  
  function FixPostion(){

  document.getElementById('onderaan').style.display = '';
  //var nLeft = document.body.clientWidth - 100;
  var nLeft = 0;
  var nTop = document.body.scrollTop + document.body.clientHeight - document.getElementById('onderaan').offsetHeight;
  document.getElementById('onderaan').style.left = nLeft;
  document.getElementById('onderaan').style.top = nTop;
}

  function FixPostion2(){

  document.getElementById('onderaan2').style.display = '';
  var mLeft = 0;
  var mTop = document.body.scrollTop + document.body.clientHeight - document.getElementById('onderaan2').offsetHeight;
  document.getElementById('onderaan2').style.left = mLeft;
  document.getElementById('onderaan2').style.top = mTop;
}


  function clickCB(theCB,val) {
    flgs = document.getElementById('flags');
    if(theCB.checked) { 
      flgs.value = (flgs.value|val);
    } else {
      flgs.value = (flgs.value&~val);
    }
    //alert(flgs.value);
  }

	function Change(val)
	{
		val.style.backgroundColor='#fd9c00';
	}
	
	function ChangeBack(val)
	{
		val.style.backgroundColor='';
	}
	
	function Go(val)
	{
		document.location.href = val;
	}
	
	function ShowDiv(val,dis)
	{
		if(document.getElementById(val).style.display == 'block')
		{ 
			document.getElementById(val).style.display = 'none'; 
			dis.style.textDecoration = 'none'; 
		}
		else 
		{ 
			document.getElementById(val).style.display = 'block'; 
			dis.style.textDecoration = 'Underline'; 
		}
	}
	
	function confirmLink(txt) 
	{ 
		if(confirm(txt)) { return true; } else { return false; } 
	}

function newImage(arg) {
 if (document.images) {
  rslt = new Image();
  rslt.src = arg;
  return rslt;
 }
}

function changeImages() {
 if (document.images) { 
  for (var i=0; i<changeImages.arguments.length; i+=2) {
   document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
  }
 }
}