function createRequestObject() {
    var ro;
    var browser = navigator.appName;
    if(browser == "Microsoft Internet Explorer"){
        ro = new ActiveXObject("Microsoft.XMLHTTP");
    }
    else{
        ro = new XMLHttpRequest();
    }
    return ro;
}
var http = createRequestObject();

// ================================ rating stuff ==============================
function updateRating(rating) {	
	document.getElementById("spanRatingMsg").innerHTML = "... saving ...";
	document.getElementById("spanRatingMsg").style.color = "Red";

	//var tabid = document.getElementById("ID");	
	var tabid = document.tabForm.ID;
	var sendto = 'tab_rating.aspx?TabID=' + tabid.value + '&Rating=' + rating;

    http.open('get', sendto);
    http.onreadystatechange = showUpdatedRating;
    http.send(null);
}

function showUpdatedRating() {
    if(http.readyState == 4) {
        var response = http.responseText;
        var update = new Array();

        if(response.indexOf('|' != -1)) {
            update = response.split('|');      
            if (update[0] == -1)
				alert("error updating");
			else  {
				document.tabForm.songAvg.value = update[0];
				document.tabForm.userRating.value = update[1];    
				//document.getElementById("SongTitle").innerHTML = update[0];
				songOff(5);
				songOn(update[0]);        
				userOff(5);
				userOn(update[1]);            
			}
			document.getElementById("spanRatingMsg").innerHTML = "your rating was saved";
			document.getElementById("spanRatingMsg").style.color = "blue";
        }
    }
}
// ============================ Image Rollover ====================
if (document.images) {
	checkon = new Image();		// Active images
	checkon.src = "images/check-sel.gif";
	checkhalf = new Image();		// Active images
	checkhalf.src = "images/check-half.gif";
	checkoff = new Image(); // Inactive images
	checkoff.src = "images/check.gif";
}
else
	alert("no document images?");

function userOn(imgNum) {
	if (document.images) { 
		for (var i = 1; i <= imgNum; i++) {
			img = "user" + i;
			document[img].src = checkon.src;
		}
	}
}
function userOff(imgNum) {
	//var userRating = document.getElementById("userRating");	
	var userRating = document.tabForm.userRating;
	if (document.images) { 
		for (var i = 1; i <= imgNum; i++) {
			if (i > userRating.value) {
				img = "user" + i;
				document[img].src = checkoff.src;
			}
		}
	}
}
function songOn(imgNum) {
	//var songAvg = document.getElementById("songAvg");
	var songAvg = document.tabForm.songAvg;
	if (document.images) { 
		for (var i = 1; i <= imgNum; i++) {
			img = "check" + i;
			document[img].src = checkon.src;
		}		
		//document.getElementById("SongTitle").innerHTML = songAvg + ' / ' + i + ' / ' + (songAvg - i + 1);
		songAvg.value = songAvg.value - i + 1;		 
		if (songAvg.value >= .25 && songAvg.value < .75) {
			img = "check" + i;
			document[img].src = checkhalf.src;
		}
	}
}
function songOff(imgNum) {
	//var songAvg = document.getElementById("songAvg");
	var songAvg = document.tabForm.songAvg;
	if (document.images) { 
		for (var i = 1; i <= imgNum; i++) {
			if (i > songAvg.value) {
				img = "check" + i;
				document[img].src = checkoff.src;
			}
		}
	}
}