function chkEnable()
{
	

	
if(document.getElementById('checkbox').checked)
{
document.getElementById('submit').disabled=false;
}
else
// leave the submit button disabled
{
document.getElementById('submit').disabled=true;
}
}


// Switches standard text in forms



function alterNate(elm){

	if (!elm.base) elm.base = elm.value

	if (elm.value == elm.base) elm.value = "";

	else if (elm.value == "") elm.value = elm.base;

}



//Functie om de kaart te switchen
var _img = new Array();
    _img[0] = new Image(); _img[0].src="/pics/kaartselector/kaart.gif";
    _img[1] = new Image(); _img[1].src="/pics/kaartselector/westerveld.gif";
    _img[2] = new Image(); _img[2].src="/pics/kaartselector/meppel.gif";
    _img[3] = new Image(); _img[3].src="/pics/kaartselector/dewolden.gif";
	_img[4] = new Image(); _img[4].src="/pics/kaartselector/hoogeveen.gif";
    _img[5] = new Image(); _img[5].src="/pics/kaartselector/middendrenthe.gif";
	_img[6] = new Image(); _img[6].src="/pics/kaartselector/coevorden.gif";
	_img[7] = new Image(); _img[7].src="/pics/kaartselector/emmen.gif";
    _img[8] = new Image(); _img[8].src="/pics/kaartselector/borgerodoorn.gif";
    _img[9] = new Image(); _img[9].src="/pics/kaartselector/aaenhunze.gif";
	_img[10] = new Image(); _img[10].src="/pics/kaartselector/assen.gif";
	_img[11] = new Image(); _img[11].src="/pics/kaartselector/tynaarlo.gif";
	_img[12] = new Image(); _img[12].src="/pics/kaartselector/noordenveld.gif";
function SwitchMap(_obj)
{
  if(!_obj)return;
  var _index = _obj.selectedIndex;
  if(!_index)return;
  var _item  = _obj[_index].value;
  if(!_item)return;
  if(_item<0 || _item >=_img.length)return;
  document.images["kaart"].src=_img[_item].src;
}



/*************************************************************************
  This code is from Dynamic Web Coding at http://www.dyn-web.com/
  Copyright 2001-3 by Sharon Paine 
  See Terms of Use at http://www.dyn-web.com/bus/terms.html
  regarding conditions under which you may use this code.
  This notice must be retained in the code as is!
*************************************************************************/

// onresize for ns4
var origWidth, origHeight;
if (document.layers) {
	origWidth = window.innerWidth; origHeight = window.innerHeight;
	window.onresize = function() { if (window.innerWidth != origWidth || window.innerHeight != origHeight) history.go(0); }
}

var cur_dealer;	// holds id of currently visible layer
function swapLayers(id) {
  if (cur_dealer) hideLayer(cur_dealer);
  showLayer(id);
  cur_dealer = id;
}

function showLayer(id) {
  var dealer = getElemRefs(id);
  if (dealer && dealer.css) dealer.css.display = "block";
}

function hideLayer(id) {
  var dealer = getElemRefs(id);
  if (dealer && dealer.css) dealer.css.display = "none";
}

function getElemRefs(id) {
	var el = (document.getElementById)? document.getElementById(id): (document.all)? document.all[id]: (document.layers)? document.layers[id]: null;
	if (el) el.css = (el.style)? el.style: el;
	return el;
}



function isInteger(s){
    var i;
    for (i = 0; i < s.length; i++){   
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    // All characters are numbers.
    return true;
}
function isAlpha(s){
	var i;
    for (i = 0; i < s.length; i++){   
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "A") || (c > "Z") (c < "a") || c < "z")) return false;
    }
    // All characters are numbers.
    return true;
}
function checkValidation2(){
	var flag =  0 ;
	Postcode = document.form1.postcode.value 
	postInt = Postcode.substring(0,4)
	postAlpha = Postcode.substring(5,7)
	checkWhiteSpace = Postcode.substring(4,5)
	var WS=" "
	if(Postcode == "" || Postcode == "null"){
		alert("Voer een valide Postcode in aub.")
		flag = 1
		return false
	}
	if(isInteger(postInt) == false){
		alert("Voer een valide Postcode in aub.")
		flag = 1
		return false
	}if(isInteger(postAlpha) == true){
		alert("Voer een valide Postcode in aub.")
		flag = 1
		return false
	}if(Postcode.indexOf(WS) != 4){
		
		alert("Voer een valide Postcode in aub.")
		flag = 1
		return false
	}if(isAlpha(postAlpha) == false){
		alert("Voer een valide Postcode in aub.")
		flag = 1
		return false
	}
	else{
		flag = 0
		return true
	}
}



function checkValidation(){
	Postcode = document.form1.postcode.value 
//if ((Postcode.search(^\d{4}[\s-]?[a-zA-Z]{2}$)) != -1){
if ((Postcode.search(/^[0-9][0-9][0-9][0-9] ?[A-Z][A-Z]$/gi)) != -1){
	var flag =  0 ;
	return true;
}
else{
	alert("Voer een valide Postcode in aub.")
	var flag =  1 ;
	return false;
}
}