function autoTab(e) {
    if(this.value.length == this.getAttribute("maxlength") && 
        e.KeyCode != 8 && e.keyCode != 16 && e.keyCode != 9) {
            new Field.activate(findNextElement(this.getAttribute("tabindex")));
        }
}

function findNextElement(index) {
    elements = new Form.getElements('shippingInfo');
    for(i = 0; i < elements.length; i++) {
        element = elements[i];
        if(parseInt(element.getAttribute("tabindex")) == (parseInt(index) + 1)) {
            return element;
        }
    }
    return elements[0];
}

function availability_check(hide,show) {
	setvalue('checking_availability','Checking availability...');
	document.getElementById(hide).style.display = 'none';
	document.getElementById(show).style.display = 'block';
}