function XHRFactory()
{
	if(window.XMLHttpRequest)
	{
		return new XMLHttpRequest();
	}

	else if(window.ActiveXObject)
	{
		return new ActiveXObject("Microsoft.XMLHTTP");
	}

	throw("XMLHTTPRequest not supported");
}

function ReplaceData(table, data)
{
	table = document.getElementById(table);
	
	while(table.childNodes.length > 0)
	{
		table.removeChild(table.firstChild);
	}
	
	table.innerHTML = data;
}

function GetTableRows(table, type)
{
	try
	{
		var xhr = XHRFactory();
	}
	
	catch(e)
	{
		return;
	}
	
	xhr.open("get", "/tablerows.php?table="+table+"&type="+type);
	
	xhr.onreadystatechange = function()
	{
		if(xhr.readyState == 4)
		{
			ReplaceData(table, xhr.responseText);
		}
	}
	
	xhr.send(null);
}

function InvertTabs(ontab, offtab)
{
	ontab = document.getElementById(ontab);
	offtab = document.getElementById(offtab);
	
	ontab.setAttribute("src", ontab.getAttribute("src").replace(/off/, "on"));
	offtab.setAttribute("src", offtab.getAttribute("src").replace(/on/, "off"));
}

function ToggleFeaturedSurveys()
{
	InvertTabs("featuredsurveys", "featuredquizzes");
	
	GetTableRows("featured", "surveys");
	
	document.getElementById("featuredwhat").firstChild.nodeValue = "Surveys";
}

function ToggleFeaturedQuizzes()
{
	InvertTabs("featuredquizzes", "featuredsurveys");
	
	GetTableRows("featured", "quizzes");
	
	document.getElementById("featuredwhat").firstChild.nodeValue = "Quizzes";
}

function ToggleNewestSurveys()
{
	InvertTabs("newestsurveys", "newestquizzes");
	
	GetTableRows("newest", "surveys");
	
	document.getElementById("newestwhat").firstChild.nodeValue = "Surveys";
}

function ToggleNewestQuizzes()
{
	InvertTabs("newestquizzes", "newestsurveys");
	
	GetTableRows("newest", "quizzes");
	
	document.getElementById("newestwhat").firstChild.nodeValue = "Quizzes";
}

function ToggleTagsSurveys()
{
	InvertTabs("tagssurveys", "tagsquizzes");
	
	GetTableRows("tagcloud", "surveys");
}

function ToggleTagsQuizzes()
{
	InvertTabs("tagsquizzes", "tagssurveys");
	
	GetTableRows("tagcloud", "quizzes");
}

function SetEvents()
{
	document.getElementById("featuredsurveys").onclick = ToggleFeaturedSurveys;
	document.getElementById("featuredquizzes").onclick = ToggleFeaturedQuizzes;
	document.getElementById("newestsurveys").onclick = ToggleNewestSurveys;
	document.getElementById("newestquizzes").onclick = ToggleNewestQuizzes;
	document.getElementById("tagssurveys").onclick = ToggleTagsSurveys;
	document.getElementById("tagsquizzes").onclick = ToggleTagsQuizzes;
}

SetEvents();