function addLoadEvent(func) 
{
	var oldonload = window.onload;
  	if (typeof window.onload != 'function') 
  	{
    	window.onload = func;
  	}
  	else 
  	{
    	window.onload = function() 
    	{
      		if (oldonload) 
      		{
        		oldonload();
      		}
      		func();
    	}
  	}
}

function getHttpObject() 
{
	if(window.ActiveXObject) 
	{
		var waystation = new ActiveXObject("Microsoft.XMLHTTP");
	} 
	else if (window.XMLHttpRequest) 
	{
		var waystation = new XMLHttpRequest();
	} 
	else 
	{
		var waystation = false;
	}
	return waystation;
}

// Adds on click behaviours to Previous / Next Buttons
function addNavigationOnClick()
{
	// Get element
	var previous = document.getElementById("video-previous");
	
	// Add onClick Event to previous
	previous.onclick = function()
	{
		// Get the offset
		var offset = parseInt(this.getAttribute("rel"));
		
		// New Offset
		if(offset < 6)
		{
			var newOffset = 0;
		}
		else
		{
			var newOffset = offset - 5;
		}
			
		// Load the data
		request = getHttpObject();
		request.open("GET", "/php/actions/videoAjax.php?offset=" + newOffset, true);
		request.onreadystatechange = updateNav; // Note there is no brackets here
		request.send(null);
		
		// Next Offset
		var previous = document.getElementById("video-previous");
		previous.setAttribute("rel", newOffset);
		
		// Previous Offset
		var next = document.getElementById("video-next");
		next.setAttribute("rel", newOffset);
		
		return false;
	}
	
	// Get element
	var next = document.getElementById("video-next");
	
	// Add onClick Event to next
	next.onclick = function()
	{
		// Get the offset
		var offset = parseInt(this.getAttribute("rel"));
		
		// Next Offset
		var newOffset = offset + 5;
		
		// Load the data
		request = getHttpObject();
		request.open("GET", "/php/actions/videoAjax.php?offset=" + newOffset, true);
		request.onreadystatechange = updateNav; // Note there is no brackets here
		request.send(null);
					
		// Next Offset
		var next = document.getElementById("video-next");
		next.setAttribute("rel", newOffset);
		
		// Previous Offset
		var previous = document.getElementById("video-previous");
		previous.setAttribute("rel", newOffset);
		
		return false;
	}
}


function updateNav()
{
	if(request.readyState == 4) 
	{
		var node = document.getElementById("video-nav");
		node.innerHTML = request.responseText;
	}
}

addLoadEvent(addNavigationOnClick);