function changeAmount(id, value, minValue) {
	if(! minValue) minValue = 0;
	else minValue *= 1;
	
	if (value > 0) {
		$(id).value = $(id).value * 1 + value;
	}
	if (value < 0 && $(id).value >= (value * -1) + minValue) {
		$(id).value = $(id).value * 1 + value;
	}
}

function changeGroupAmount(id, value) {
	if (value > 0) {
		$('groupamount_'+id).value = $('groupamount_'+id).value * 1 + value;
	}
	if (value < 0 && $('groupamount_'+id).value >= value * -1) {
		$('groupamount_'+id).value = $('groupamount_'+id).value * 1 + value;
	}

	var items = $$('input.group_' + id);
	for (var i=0; i<items.length; i++) {
		items[i].value = $('groupamount_'+id).value;
	}
}

function changeGroupProduct(id) {
	var items = $$('select.productselect_' + id);
	for (var i=0; i<items.length; i++) {
		items[i].value = $('groupproduct_'+id).value;
	}
}

function getNextId(divid) {
	i = 1;
	while ($(divid+'_'+i) != null) {
		i++;
	}
	return i;
}

//Global Variable saveChanges must be set in the template because its a message
//depening on current affiliate
function changedCart(changedtextonly) {
	$('recalculate_cart').show();
	$('continue').value = saveChanges;
	
	if (!changedtextonly) {
		var items = $$('td.col_sum');
		for(i=0; i < items.length; i++) {
			items[i].addClassName('outdated');
    	}
    }
}

function resetDropDowns() {
	var items = $$('.productselect');
	for(i=0; i < items.length; i++) {
		if (items[i].value == -1) {
			items[i].value = items[i].defaultValue;
		}
    }
}

function deleteItem(cart_item_id, group_id) {
	Effect.Fade('row_'+cart_item_id);
	$('amount_'+cart_item_id).removeClassName('group_'+group_id);
	$('amount_'+cart_item_id).value = 0;  		
}