//	open external links in a new window - replaces target="_blank"
	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") == "external" ) anchor.target = "_blank"; 
		} 
	} 

//	preload images
	function preload_images () {
		arImageSrc = new Array ();
		arImageList = new Array ();
		for (counter in arImageSrc) {
			arImageList[counter] = new Image();
			arImageList[counter].src = arImageSrc[counter];
		}
	}


//	add given page to favourites (bookmark)
	function setBookmark ( url, str ) {
		if ( str == '' ) str = url;
		if ( document.all ) window.external.AddFavorite( url, str );
		else alert( 'Sorry, this function only works in Internet Explorer.\n\nPlease press CTRL and D to add a bookmark to \n"' + str + '".' );
	}

//	toggle a given elements visibility
	function toggle (el) {
		if ( document.getElementById(el).style.display == 'none' ) {
			document.getElementById(el).style.display = '';
		} else {
			document.getElementById(el).style.display = 'none';
		}
	}

//	show a given element
	function show (el) {
		if ( document.getElementById(el) != undefined ) document.getElementById(el).style.display = '';
	}

//	initiate an AJAX object
	function ajaxFunction () {
		var xmlHttp;
		try {
			// Firefox, Opera 8.0+, Safari
			xmlHttp=new XMLHttpRequest();
		}
		catch (e) {
			// Internet Explorer
			try {
				xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
			}
			catch (e) {
				try {
					xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
				}
				catch (e) {
					alert("Your browser does not support AJAX!");
					return false;
				}
			}
		}
	}

	function activate_current_nav() {
		var fullpath = location.pathname;


		var patharray = fullpath.split('/');
		var filepos = patharray.length - 1;
		var filename = patharray[filepos];

		var filearray = filename.split('.');
		var filebase = filearray[0];

		switch ( filebase ) {
	
			case 'how_we_do_it' :
				document.getElementById('how_we_do_it').className = 'selected';
				break;

			case 'who_we_are' :
				document.getElementById('who_we_are').className = 'selected';
				break;

			case 'case_studies' :
			case 'case_studies_paul' :
				document.getElementById('case_studies').className = 'selected';
				break;

			case 'news' :
				document.getElementById('news').className = 'selected';
				break;

			case 'file_manager' :
				document.getElementById('file_manager').className = 'selected';
				break;

			case 'clients' :
				document.getElementById('clients').className = 'selected';
				break;

			case 'links' :
				document.getElementById('links').className = 'selected';
				break;

			case 'contact' :
				document.getElementById('contact').className = 'selected';
				break;
	
			default :
				document.getElementById('index').className = 'selected';
				break;
	
		}
	
	}

//	perform the following functions when the page loads
	window.onload = function(e) {
		externalLinks();
		activate_current_nav();
	}