/**
			 * Function to handle calls to the server.
	 * Creates an XMLHTTP or XMLHttpRequest object
			 * then retrieves the url 'url' and passes the return to alertContents() function.
			 * @param String url The url to retrieve from the server.
			 * NOTE: url must not reside on a third-party server, as HTTP request object prevents it.
			 * @return Boolean False returned if an XMLHTTP or XMLHttpRequest instance cannot be created.
			*/
			function loadUrlIntoContentPane (url, contentPane) {
			
				var http_request = false;
				
				//check to see if it can find an XMLHttpRequest attribute
				//should find one if user is using a Mozilla or Safari based browser..
				if(window.XMLHttpRequest) {
					http_request = new XMLHttpRequest();
					
					//not sure what this does yet...
					if(http_request.overrideMimeType) {
						http_request.overrideMimeType('text/xml');
					}
					
				//couldn't find an XMLHttpRequest, 
				//so lets try & see if we have ActiveXObject attribute
				//if so, then user is using an IE based browser
				} else if(window.ActiveXObject) {
					try {
						//try & create an Msxml2 version
						http_request = new ActiveXObject("Msxml2.XMLHTTP");
					} catch (e) {
						try {
						//if we can't make an Msxml2 version, try with the Microsoft version
							http_request = new ActiveXObject("Microsoft.XMLHTTP");
						}catch (e) {}
					}
				}
				
				//if we can't make a XMLHTTP or XMLHttpRequest instance,
				//let the user know. They are probably using an old version of browser,
				//or dont have JavaScript enabled.. in which case an alert would be useless?
				if(!http_request) {
					alert('Giving up :( Cannot create an XMLHTTP instance');
					return false;
				}
				
				//define onreadystatechange as being an on-the-fly function that calls alertContents()
				http_request.onreadystatechange = function() { updateContentPane(http_request, contentPane); };
				
				//make requests to server.
				//open() parameters = HTTP request method type, url of page to request, whether call is asynchronous or not
				
				try {
				http_request.open('GET', url, true);
				//POST parameters to send
				//should be in form of a query string. eg. parameter=value&2ndparameter=2ndvalue&so=on
				//note: if using POST need to change mime-type:
				//http_request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
				http_request.send("");
				} catch (e) {}
				
			}//end of makeRequest() function
			
			/**
			 * Function to return data from server.
			 * @param XMLHTTP http_request An XMLHTTP or XMLHttpRequest object being returned by the server
			*/
			function updateContentPane(http_request, contentPane) {
				//check if our http_request has its state as 'completed'
				//readyState values:
				//0 (uninitialized);
				//1 (loading);
				//2 (loaded);
				//3 (interactive);
				//4 (completed);
				if(http_request.readyState == 4) {
					//check to see that the Status code is '200' (OK).
					//for full list of status codes see:
					//www.w3.org/Protocols/rfc2616/rfc2616-sec10.html
					//if you are running from localhost under windows status will return 0.
					//only put this in for windows developers.
					if(http_request.status == 200 || http_request.status == 0) {
						//if its all OK, then alert() out the text.
						try {
						response = http_request.responseText;
						document.getElementById(contentPane).innerHTML = response;
						} catch (e) {}
					} else {
						//if not, then notify user it died.
						alert('There was a problem with the request.');
					}//end of else
							
				}//end of if readyState == 4
			}//end of alertContents() function
			
			
			/**
			deprecated for the new way of passing arrays in.. makes things easier
			
			function loadUrlsIntoPanes(masterUrl, masterPane, subUrl, subPane) {
				loadUrlIntoContentPane(masterUrl, masterPane);
				loadUrlIntoContentPane(subUrl, subPane);
			}
			**/
			
			
			/**
			 * Function to handle multiple pane updates.
			 * cycles thru both the urls & panes arrays.
			 * if both the url & pane are set, it'll update.
			 *
			 * Note: when calling this function remember to get your
			 * urls & panes in order.. don't go trying to update panes that don't exist
			 */
			function loadUrlsIntoPanes(urls, panes) {
				//loop thru the urls array
				for(i= 0; i < urls.length; i++) {
					//check that the url & pane are valid
					if((urls[i] != "" && urls[i] != null) && (panes[i] != "" && panes[i] != null)) {
						//if so load the url into the pane
						loadUrlIntoContentPane(urls[i], panes[i]);						
					}
				}
			}
			
			
			/**
			 * Function to toggle display of an element, used in the left menu to show / hide sections
			 * @param String targetId the id assigned to the element to be toggled.
			*/
			function toggle(targetId, targetImg){
			plus = "images/plus.gif";
			minus = "images/minus.gif";			
			
  				if (document.getElementById){
        			target = document.getElementById( targetId );
        			img = document.getElementById(targetImg);
        			
	           		if (target.style.display == "none"){
	              		target.style.display = "";
	              		img.src = minus;
	           		} else {
	              		target.style.display = "none";
	              		img.src = plus;
	           		}
     			}
			}