var nosku = "None";
var noimage = "none.jpg";
var compareurl = "/support/compare/compare.aspx?";
var compdefault = "comp.jpg";
var compselected = "comp_selected.jpg";
var products = [
            new Array(nosku, noimage, 0, ""),
            new Array(nosku, noimage, 0, ""),
            new Array(nosku, noimage, 0, ""),
            new Array(nosku, noimage, 0, "")];

function clearCompare() {
    var checks = document.getElementsByName("compCheck");
    for (i in checks)
        checks[i].checked = false;
}

function includeCompare(name, sku, id, image) {
    var control = document.getElementById(name);
    if (control != null) {
        if (control.checked) {
            var added = false;
            for (i in products) {
                if (products[i][2] == 0) {
                    products[i][0] = sku;
                    products[i][1] = image;
                    products[i][2] = id;
                    products[i][3] = name;
                    var label = document.getElementById(name + "label");
                    if (label != null)
                        label.src = compselected;
                    added = true;
                    break;
                }
            }
            if (!added) {
                alert("Only four products may be compared. To add this product, please uncheck the compare box for another product.");
                control.checked = false;
            }
        } else {
            for (i in products) {
                if (products[i][2] == id) {
                    products[i][0] = nosku;
                    products[i][1] = noimage;
                    products[i][2] = 0;
                    products[i][3] = "";
                }
            }
            var label = document.getElementById(name + "label");
            if (label != null)
                label.src = compdefault;
        }
    }
    drawPreview();
}

function labelClick(name, sku, id, image) {
    var control = document.getElementById(name);
    if (control != null) {
        if (control.checked) {
            doComparison();
        } else {
        control.checked = true;
            includeCompare(name, sku, id, image);
        }
    }
}

function removeCompare(id) {
    if (id == 0)
        return;
    for (i in products) {
        if (products[i][2] == id) {
            var control = document.getElementById(products[i][3]);
            control.checked = false;
            products[i][0] = nosku;
            products[i][1] = noimage;
            products[i][2] = 0;
            products[i][3] = "";
        }
    }
    drawPreview();
}

function drawPreview() {
    var pane = 0;
    for (var i = 0; i < 4; i++) {
        if (products[i][2] != 0) {
            var img = document.getElementById("pick" + pane);
            img.src = products[i][1];
            img.alt = products[i][0];
            img.onclick = function () { removeCompare(products[i][2]) };
            pane++;
        }
    }
    for (; pane < 4; pane++) {
        var img = document.getElementById("pick" + pane);
        img.src = noimage;
        img.alt = nosku;
        img.onclick = function () { return; };
    }
}

function doComparison() {
    var url = compareurl;
    var first = true;
	var count = 0;
	
	
    for (i in products) {
        if (products[i][2] != 0) {
			count++;
            if (!first) {
                url += "&compare" + (parseInt(i) + 1) + "=" + products[i][0];
            } else {
                url += "compare" + (parseInt(i) + 1) + "=" + products[i][0];
                first = false;
            }
        }
    }
	if (count < 2)
	{
		alert("Please select at least two products to compare.");
		return false;
	}
    //var newwindow = window.open(url, 'Air-n-Water Comparison', 'height=400,width=600');
    //if (window.focus) { newwindow.focus() }
    window.location = url;
    return false;
}