function addEvent(elm, evType, fn, useCapture) {
	if (elm.addEventListener) {
		elm.addEventListener(evType, fn, useCapture);
		return true;
    }
	else if (elm.attachEvent) {
		var r = elm.attachEvent('on' + evType, fn);
		return r;
	}
	else {
		elm['on' + evType] = fn;
	}
}

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

function verify(obj) {
    var tCart = document.getElementsByName('cart_quantity');
    if (tCart[0]) {
        if (tCart[0].onsubmit) {
            if (tCart[0].onsubmit()) {
                tCart[0].submit();
            }
        }
    }
    return false;
}

function verify_options() {
    var tCart = document.getElementsByName('cart_quantity');
    var HasOptions = false;
    
    if (tCart) {
        tCart = tCart[0];
        for (var t in tCart) {
            if (t.slice(0,3) == "id[") {
                HasOptions = true;
               	var x = document.getElementsByName(t);
                for(var i=0;i<x.length; i++) {
                    if (x[i].checked == true || x[i].type == "hidden") {
                        return true;
                    }
                }
            }
        }
        if (HasOptions == true) {
            alert("You must select an option."); 
            return false;
        }
    }
}

function attach_require() {
    var tForms = document.getElementsByTagName('form');
    for(var i=0;i<tForms.length;i++) {
        var tForm = tForms[i];
        if (tForm.name == "cart_quantity") {
            tForm.onsubmit = verify_options;
        }
    }
}
addLoadEvent(attach_require);