var demoLang = "";
var demoOS = "windows";
var demoText = new Object();
var demoTitle = new Object();

// returns array with total and visible steps in HTML ([total,visible])
function countStepsInHTML() {
	var element = document.getElementById("steps");
	var subdivs = element.getElementsByTagName("div");
	var count = 0;
	var visible = 0;
	for(var i=0; i < subdivs.length; i++) {
		if(subdivs[i].className == "step" || subdivs[i].className == "step current"){
			count++;
			if(subdivs[i].style.display == '') {
				visible++;
			}
		}
	}
	var result = new Array(count,visible);
	return result;
}

function demoStep(step,onload) {
	window.location.href = "#"+demoOS+"-"+step;
	if (!document.getElementById) return true;
	var img = document.getElementById('screenshot-img');
	var steps = Array();
	for (var j=0; j < demoText[demoOS].length; j++) {
		var tmp = j + 1;
		steps.push(document.getElementById('step'+tmp));
	}
     
	stepslength = steps.length;

    for (var i=0; i < stepslength; i++) {
        var	curstep = step-1;
		steps[i].className = (i==curstep ? 'step current' : 'step');
	}

	//var newSource = "http://c.skype.com/i_preairlift/screenshots/step"+step+"_"+demoOS+"_new.png";
	//var newSource = "http://skype.tom.com/image/2.gif";
	
	var newSource = "screenshots.png/step"+step+"_"+demoOS+"_new.png";
	if (navigator.platform == "Win32" && navigator.appName == "Microsoft Internet Explorer") {
		img.src = "/i_preairlift/screenshots/trans.gif";
		bgPng(newSource,onload);
	} else {
		img.style.background = "url("+newSource+")  no-repeat center;";
	}
	
	return false;
}

function demoSwitch(os) {
	openTab(os);
	countStepsInHTML();
	if (!document.getElementById) return true;
	demoOS = os;
    var stepTexts = Array();
	var stepTitles = Array();
	for (var j=0; j < demoText[demoOS].length; j++) {
		var tmp = j + 1;
		stepTexts.push(document.getElementById('step'+tmp+'txt'));
		stepTitles.push(document.getElementById('step'+tmp+'hdr'));
	}
	
	stepslength = stepTexts.length;
	for (var i=0; i < stepslength; i++) {
		if(i < stepslength - 1) {
			nextStep = i + 2;
			nextStepHtml = "<br /><a onclick='demoStep("+nextStep+")'>Next screenshot &#0187;</a>"
		} else {
			nextStepHtml = "";
		}	
		stepTexts[i].innerHTML = demoText[demoOS][i] + nextStepHtml;
		stepTitles[i].innerHTML = demoTitle[demoOS][i];
	}
	
	// hide exessive steps or show extra steps from HTML
	var totalStepsInHTML = countStepsInHTML();
	if (demoText[demoOS].length < totalStepsInHTML[1]) {
		for(var s=totalStepsInHTML[0]; s > demoText[demoOS].length; s--) {
			document.getElementById('step'+s).style.display = 'none';
			//console.log("turned step"+s+": hidden");
		}
	} else {
		if(demoText[demoOS].length > totalStepsInHTML[1]) {
			for(var s=totalStepsInHTML[1]; s < demoText[demoOS].length; s++) {
				var nextStep = s + 1;
				document.getElementById('step'+nextStep).style.display = '';
				//console.log("turned step"+nextStep+": visible");
			}
		}
	}
	demoStep(1,false);
	return false;
}

function bgPng(fileSource,onload) {
	var img = document.getElementById("screenshot-img");
	if(!onload) {
		img.style.backgroundImage = "url('/i_preairlift/screenshots/trans.gif')";
	}
	img.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='"+fileSource+"', sizingMethod='crop')";
}

function detectAnchor(os) {
	var strID = window.document.location.toString();
	var intLen = strID.indexOf('#');
	var intSeperator = strID.indexOf("-",intLen);
	
	// if url contains an anchor, then it links to sertain os/step
	if(intLen > -1) {
		step = strID.substring(intSeperator+1);
		os = strID.substring(intLen+1,intSeperator);
		linkedTo(os,step)
	} else {
		demoSwitch(os);
	}
}

function linkedTo(os,step) {
	demoSwitch(os);
	demoStep(step);
}