pic1= new Image(); 
pic1.src="images/lounge.jpg";
pic2= new Image(); 
pic2.src="images/kitchen.jpg";
pic3= new Image(); 
pic3.src="images/bedroom.jpg";
pic4= new Image(); 
pic4.src="images/zwembad.jpg";
pic5= new Image(); 
pic5.src="images/pingpong.jpg";

function swap(s,n){
  var el;
  if( n && document.images && document.images[n] )
   el = document.images[n];
  else if( event.srcElement && event.srcElement.src )
   el = event.srcElement;
  if( el )
   el.src = s;
}

function setStyle( id ) {
		document.getElementById( id ).style.border = '6px solid #DCB692';
}
function setStyleBack( id ) {
		document.getElementById( id ).style.border = '6px solid #ffffff';
}

function externalLinks() {
 if (!document.getElementsByTagName) return;
 var anchors = document.getElementsByTagName("a");
 for (var i=0; i<anchors.length; i++) {
   var anchor = anchors[i];
   if (anchor.getAttribute("href") &&
       anchor.getAttribute("rel") == "extern")
     anchor.target = "_blank";
 }
}
window.onload = externalLinks;