// JavaScript Document
var numMenus;
var menuGraphOn;
var menuGraphOff;
var menuLink;
var URLrequest = null;
var contentHeight = 0;
var initLoaded = false;

function init() {
	contentHeight = window.innerHeight - 110;
	//alert(contentHeight);
	window.document.getElementById("content").setAttribute("height", contentHeight);
	
	numMenus = 5;
	menuGraphOn = new Array(numMenus);
	menuGraphOff = new Array(numMenus);
	menuLink = new Array(numMenus);
	
	menuGraphOn[0] = "graphs/bjkhome.png";
	menuGraphOff[0] = "graphs/bjkhome_off.png";
	menuLink[0] = "main.html";
	
	menuGraphOn[1] = "graphs/about.png";
	menuGraphOff[1] = "graphs/about_off.png";
	menuLink[1] = "about.html";
	
	menuGraphOn[2] = "graphs/publications.png";
	menuGraphOff[2] = "graphs/publications_off.png";
	menuLink[2] = "publications.html";

	menuGraphOn[3] = "graphs/showcase.png";
	menuGraphOff[3] = "graphs/showcase_off.png";
	menuLink[3] = "showcase.html";
	
	menuGraphOn[4] = "graphs/software.png";	
	menuGraphOff[4] = "graphs/software_off.png";	
	menuLink[4] = "software.html";
	
	for ( var i = 0; i < numMenus; i++) {
			window.document.getElementById("menu_" + i).setAttribute("class", "menuoff");
			window.document.getElementById("menu_img_" + i).setAttribute("src", menuGraphOff[i]);
	}
	initLoaded= true; // used in checkedFramed() function in content HTML
	menuParam = getURLparam("menu");
	if ((menuParam > 0) && (menuParam < numMenus)) 
		togglemenu(menuParam); 
	 else 
		togglemenu(0);
}

function getURLparam(param) {
  param = param.replace(/[\[]/,"\\\[").replace(/[\]]/,"\\\]");
  var regexS = "[\\?&]"+param+"=([^&#]*)";
  var regex = new RegExp( regexS );
  var results = regex.exec( window.location.href );
  if( results == null )
    return "";
  else
    return results[1];
}


function togglemenu(theMenu) {
	for ( var i = 0; i < numMenus; i++) {
			window.document.getElementById("menu_" + i).setAttribute("class", "menuoff");
			window.document.getElementById("menu_img_" + i).setAttribute("src", menuGraphOff[i]);
	}
	window.document.getElementById("menu_" + theMenu).setAttribute("class", "menuon");
	//document.getElementById("menu_" + theMenu).setAttribute("bgcolor", "#ffffff");
	window.document.getElementById("menu_img_" + theMenu).setAttribute("src", menuGraphOn[theMenu]);
	//loadHTML(menuLink[theMenu]);
	window.document.getElementById("content").src = menuLink[theMenu];
} //function

function loadHTML(url) {
	if (window.XMLHttpRequest) {
		try { 
			URLrequest = new XMLHttpRequest();
		} catch(e) {
			URLrequest = null;
		}
	} else if (window.ActiveXObject) {
		try {
			URLrequest = new ActiveXObject("Msxml2.XMLHTTP");
		} catch(e) {
			URLrequest = null;
		}
	}
	if (URLrequest) {
		URLrequest.open("GET", url, true);
		URLrequest.onreadystatechange = processRequest;
		URLrequest.setRequestHeader("Content-Type", "text/html");
		URLrequest.send("");
	}
}

function processRequest() {
	if (URLrequest.readyState == 4 && URLrequest.status == 200) {
		var htmlDoc = URLrequest.responseText;
		if (htmlDoc) {
			window.document.getElementById("content").innerHTML = htmlDoc;
		}
	}
}