var curSel = null;
var myDiv; //main video div
var loading;
function setDivs()
{
	loading = document.getElementById("loadDiv");
	myDiv 	= document.getElementById("videoCont");
}
function switchSelection(newSel)
{
	newSel.style.background = "#F2F2F2";	
	if (curSel!=null) curSel.style.background = "white";
	curSel = newSel;	
}

// holds an instance of XMLHttpRequest
var xmlHttp = createXmlHttpRequestObject();
// creates an XMLHttpRequest instance
function createXmlHttpRequestObject()
{
	// will store the reference to the XMLHttpRequest object
	var xmlHttp;
	// this should work for all browsers except IE6 and older
	try
	{
		// try to create XMLHttpRequest object
		xmlHttp = new XMLHttpRequest();
	}
	catch(e)
	{
		// assume IE6 or older
		var XmlHttpVersions = new Array("MSXML2.XMLHTTP.6.0",
		"MSXML2.XMLHTTP.5.0",
		"MSXML2.XMLHTTP.4.0",
		"MSXML2.XMLHTTP.3.0",
		"MSXML2.XMLHTTP",
		"Microsoft.XMLHTTP");
		// try every prog id until one works
		for (var i=0; i<XmlHttpVersions.length && !xmlHttp; i++)
		{
			try
			{
				// try to create XMLHttpRequest object
				xmlHttp = new ActiveXObject(XmlHttpVersions[i]);
			}
			catch (e) {}
		}
	}
	// return the created object or display an error message
	if (!xmlHttp)
		alert("Error creating the XMLHttpRequest object.");
	else
		return xmlHttp;
}
// called to read a file from the server
function showVideo(param)
{
	// only continue if xmlHttp isn't void
	if (xmlHttp)
	{
		// try to connect to the server
		try
		{
			// initiate reading the from the server
			var params = "param=" + escape(param);
			xmlHttp.open("POST", "include/getVideo.php", true);
			
			//Send the proper header information along with the request
			xmlHttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
			xmlHttp.setRequestHeader("Content-length", params.length);
			xmlHttp.setRequestHeader("Connection", "close");			
			
			xmlHttp.onreadystatechange = handleRequestStateChange;
			xmlHttp.send(params);
			
			
			s = document.getElementById(param);
			if (s!=curSel)
				switchSelection(s);	
		}
		// display the error in case of failure
		catch (e)
		{
			//alert("Can't connect to server:\n" + e.toString());
		}
	}
}	
// function that handles the HTTP response
function handleRequestStateChange()
{
	// display the status of the request
	if (xmlHttp.readyState == 1)
	{
		myDiv.innerHTML = '';
		loading.style.visibility = "visible";
		myDiv.style.background = "white";
	}
	// when readyState is 4, we also read the server response
	else if (xmlHttp.readyState == 4)
	{
		// continue only if HTTP status is "OK"
		if (xmlHttp.status == 200)
		{
			try
			{
				// read the message from the server
				response = xmlHttp.responseText;
				loading.style.visibility = "hidden";
				// display the message
				myDiv.innerHTML = response;
				
				myDiv.style.background = "#AAA9A9";
				
			}
			catch(e)
			{
				// display error message
				//alert("Error reading the response: " + e.toString());
			}
		}
		else
		{
			// display status message
			alert("There was a problem retrieving the data:\n" +
			xmlHttp.statusText);
		}
	}
}