var xmlHttp;

function change_song()
{
	var selectBox = document.getElementById("song_select");
	var options = selectBox.options;
	var midname = options[selectBox.selectedIndex].value;
	if (window.XMLHttpRequest)
	{
		xmlHttp = new XMLHttpRequest();
	}
	else if (window.ActiveXObject)
	{
		xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
	}
	else
	{
		document.getElementById("song_display").innerHTML = "Your browser doesn't appear to support AJAX.";
	}
	xmlHttp.onreadystatechange = change_song_callback;
	xmlHttp.open("GET", midname + ".html", true);
	xmlHttp.send(null);
}

function change_song_callback()
{
	if (xmlHttp.readyState == 4)
	{
		document.getElementById("song_display").innerHTML = xmlHttp.responseText;
	}
}

function show_drum_path(midname)
{
	var diffSelect = document.getElementById("drumdifficulty");
	var platSelect = document.getElementById("drumplatform");
	var diff = diffSelect.options[diffSelect.selectedIndex].value;
	var plat = platSelect.options[platSelect.selectedIndex].value;
	var url = "../drumstats/" + midname + "_" + diff + "_" + plat + ".html";
	if (window.XMLHttpRequest)
	{
		xmlHttp = new XMLHttpRequest();
	}
	else if (window.ActiveXObject)
	{
		xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
	}
	else
	{
		document.getElementById("drum_display").innerHTML = "Your browser doesn't appear to support AJAX.";
	}
	xmlHttp.onreadystatechange = show_drum_path_callback;
	xmlHttp.open("GET", url, true);
	xmlHttp.send(null);
}

function show_drum_path_callback()
{
	if (xmlHttp.readyState == 4)
	{
		document.getElementById("drum_display").innerHTML = xmlHttp.responseText;
	}
}

function clear_drum_path()
{
	document.getElementById("drum_display").innerHTML = "";
}

function get_cutoffs(midname)
{
	var instruments = new Array("drums", "bass", "guitar", "vocals");
	var query = "";
	for (var i=0; i<4; i++)
	{
		var selectBox = document.getElementById("cutoff_" + instruments[i]);
		query += instruments[i] + "=" + selectBox.options[selectBox.selectedIndex].text + "&";
	}
	var platSelectBox = document.getElementById("cutoff_platform");
	query += "platform=" + platSelectBox.options[platSelectBox.selectedIndex].value;
	if (window.XMLHttpRequest)
	{
		xmlHttp = new XMLHttpRequest();
	}
	else if (window.ActiveXObject)
	{
		xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
	}
	else
	{
		document.getElementById("cutoff_display").innerHTML = "Your browser doesn't appear to support AJAX.";
	}
	xmlHttp.onreadystatechange = show_cutoffs_callback;
	var url = "../cutoffs/single.cgi?songname=" + midname + "&" + query;
	xmlHttp.open("GET", url, true);
	xmlHttp.send(null);
}

function show_cutoffs_callback()
{
	if (xmlHttp.readyState == 4)
	{
		document.getElementById("cutoff_display").innerHTML = xmlHttp.responseText;
	}
}