var xmlhttp = false;

if (!xmlhttp && typeof XMLHttpRequest!='undefined')  {
	xmlhttp = new XMLHttpRequest();
}

function getAlbumDetailsAjax(albumID) {
	xmlhttp=GetXmlHttpObject();
	if (xmlhttp==null) {
		alert ("Browser does not support HTTP Request");
		return;
	} 

	var url = "discography_get.php";
	url = url + "?album=" + albumID;
	xmlhttp.open("GET", url, true);

	xmlhttp.onreadystatechange=function() {
		if (xmlhttp.readyState==4 || xmlhttp.readyState=="complete") {
			Element.hide('albumDetails');
			new Effect.Appear(document.getElementById('albumDetails'));
			document.getElementById('albumDetails').innerHTML = xmlhttp.responseText;
		}
	}

	xmlhttp.send(null);
	return false;
}

function GetXmlHttpObject() {
	var objXMLHttp=null;
	if (window.XMLHttpRequest) {
		objXMLHttp=new XMLHttpRequest();
	}
	else if (window.ActiveXObject) {
		objXMLHttp=new ActiveXObject("Microsoft.XMLHTTP");
	}
	return objXMLHttp;
} 

function setAlbumSlider() {
	var albumSlider = new Control.Slider('scrollHandleAlbum', 'scrollBarAlbum', {
		axis: 'vertical',
		onSlide: function(v) { scrollVertical(v, $('albumTracks'), albumSlider);  },
		onChange: function(v) { scrollVertical(v, $('albumTracks'), albumSlider); }
	});
	
	// disable vertical scrolling if text doesn't overflow the div
	if ($('albumTracks').scrollHeight <= $('albumTracks').offsetHeight) {
		albumSlider.setDisabled();
		$('scrollBarAlbum').hide();
	}
	
	/* alert($('albumTracks').scrollHeight + " " + $('albumTracks').offsetHeight); */
}
	
// scroll the element vertically based on its width and the slider maximum value
function scrollVertical(value, element, slider) {
	element.scrollTop = Math.round(value/slider.maximum*(element.scrollHeight-element.offsetHeight));
}

function toggle(list, noOfId) {
	var listElementStyle = document.getElementById("track" + list).style;
	var triggerElementStyle = document.getElementById("toggle" + list).style;
	
	for (i = 1; i <= noOfId; i++) {
		document.getElementById("track" + i).style.display = "none";
		document.getElementById("toggle" + i).style.textDecoration = "none";
	}
	listElementStyle.display = "block";
	triggerElementStyle.textDecoration = "underline";
}