var request = false;
  
function makeRequest(url) {
      
	if (window.XMLHttpRequest) {
		request = new XMLHttpRequest();
			if (request.overrideMimeType) {
				request.overrideMimeType('text/xml');
				}
	} else if (window.ActiveXObject) {
		try {
			request = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try {
				request = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (e) {}
         }
      }
      if (!request) {
         alert('Cannot create XMLHTTP instance');
         return false;
      }
      request.onreadystatechange = showNewContents;
      request.open('GET', (url +makeUnique()), true);
      request.send(null);
}

function showNewContents() {
      if (request.readyState == 4) {
         if (request.status == 200) {

            var responseText = request.responseText;
	    var newContent = document.createElement('div');
	    newContent.id = "divpc";
	    newContent.innerHTML = responseText;
	    
	    var oldContent = document.getElementById("divpc");
	    oldContent.parentNode.replaceChild(newContent, oldContent);
	    enableAjaxInLinks(newContent);

         } else {
            alert('There was a problem with the request.');
         }
      }
}

//function to receive all links in the current page and add ajax functionality to their href property 
function enableAjaxInLinks(element){
	if(!element){																		// if no argument is passed, retrieve all current document link elements														
	var pageLinks = window.document.links;
		for (j = 0; j<pageLinks.length; j++){
				if(pageLinks[j].href.indexOf('http://www.roelstuin.nl')!=-1){
				pageLinks[j].href = "javascript:makeRequest('" + pageLinks[j].href + "')"
				}else{
					pageLinks[j].target="blank";
				}
			}				
			}else{																	// if an element is passed as an argument, retrieve only the links within that element
			var elementLinks = element.getElementsByTagName('a')
				for (k = 0; k<elementLinks.length; k++){
					if(elementLinks[k].href.indexOf('http://www.roelstuin')!=-1 && elementLinks[k].href.indexOf('#')==-1){
					elementLinks[k].href = "javascript:makeRequest('" + elementLinks[k].href + "')"
					}else if(elementLinks[k].href.indexOf('#')!=-1){
					elementLinks[k].href = elementLinks[k].href
					}else{
						elementLinks[k].target="blank";
					}
				}
			}
}

//function to make each url request unique>>>>handy during development when (proxy) cashing is not welcome! Just add "makeUnique to the url value"
function makeUnique(){
	var date = new Date();
	var seconds = date.getSeconds();
	return "?time=" + seconds;	
}

function startPage(){
	enableAjaxInLinks();
	makeRequest("home_A.html");								// this call ensures that template b is loaded in as the first page 
}