var linkid;
var contentid;

function showSub(linkid,contentid) {

	function $(ID) {
		return document.getElementById(ID);
	}
	
	function toggle(element) {
	    visible(element) ? hide(element) : show(element);
	}
	
	function visible(element) {
		 return element.style.display != 'none';
	}
	
	function hide(element) {
		element.style.display = 'none';
	}
	
	function show(element) {
		element.style.display = '';
	}
	
	function addClassName(element, className) {
		element.className = element.className + ' ' + className;
	}
	
	function removeClassName(element, className) {
		var classArr = element.className.split(' ');
		classArr = removeFromArray(classArr,className);
		element.className = classArr.join(' '); 
	}
	
	function removeFromArray(array,string) {
		var results = Array();
		for (var i = 0, length = array.length; i < length; i++) {
			if(array[i] != string) {
				results.push(array[i]);
			}
		}
		return results;
	}
	
		
	var link = $(linkid)
	var content = $(contentid);
	
	toggle(content);
	visible(content) ? addClassName(link,'openlink-act') : removeClassName(link,'openlink-act');
}

////////////////////////////////////////////////////////////////////////////////////////////////////

function getURLParam(strParamName) {
	var strReturn = "";
	var strHref = window.location.href;
	if ( strHref.indexOf("?") > -1 ) {
		var strQueryString = strHref.substr(strHref.indexOf("?"));
		var aQueryString = strQueryString.split("&");
		for ( var iParam = 0; iParam < aQueryString.length; iParam++ ) {
			if (aQueryString[iParam].indexOf(strParamName + "=") > -1 ) {
				var aParam = aQueryString[iParam].split("=");
				strReturn = aParam[1];
				break;
			}
		}
	}
	return unescape(strReturn);
}

////////////////////////////////////////////////////////////////////////////////////////////////////

function getCurrDocName () {
	var path = window.location.pathname.split('/');
	return path[path.length -1];
}

////////////////////////////////////////////////////////////////////////////////////////////////////

// Get number of current step
function getDocNum() {
					
	// default to 1
	if ((num= getURLParam("num")) == "") {
		return '1';
	}
	
	// else
	return num;

} // getDocNum()			

////////////////////////////////////////////////////////////////////////////////////////////////////

// Set the picture
function setPicture(display_elem) {
	
	// create new image
	var normal_image= new Image();
	var mouseover_image= new Image();
	
	// Determine document number
	var num= getDocNum();
	
	// preload images
	normal_image.src= "../images/guide_" + tourNum + "." + num + ".png";
	mouseover_image.src= "../images/guide_" + tourNum + "." + num + "_next.png";
	
	if (display_elem == 'normal_image') {
		document.getElementById("img").src= normal_image.src;
	} else if (display_elem == 'mouseover_image') {
		document.getElementById("img").src= mouseover_image.src;
	} else {
		alert("Parameter display_elem= '" + display_elem + "'is unknown");
	}
} // setPicture(display_elem)

////////////////////////////////////////////////////////////////////////////////////////////////////

// Fill the description div
function setDescription() {
	
	// Set text according to document number
	var num= getDocNum();

	if (num == 0  ||  num >= descr.length) {
		alert("setDescription(): Number \'" + num + "\' is not part of available descriptions!");
	} else {
		document.getElementById("descr").innerHTML= descr[num];
	}
	
} // setDescription()

////////////////////////////////////////////////////////////////////////////////////////////////////

function openWindow(url) {
	MyWindow= window.open(url, "_blank", "width=1014,height=719,resizable=yes,left=0,top=0,status=no");
	MyWindow.focus();
}