function showPriceList() {
    var el = $('pricelist');
    if (el) {
        showMask();
        var left = Math.max(0, (window.getSize().x - 600) / 2);
        var top = (window.getScroll().y + 200);
        el.setStyles({ 'left': left + 'px', 'top': top + 'px', 'display': 'block' });
        
        var txt = $('pl_email');
        if (txt) txt.focus();
    }    
}
function hidePriceList() {
    hideMask();
    var el = $('pricelist');
    if (el) el.setStyle('display', 'none');
}
function validatePriceList() {
    var el = $('pl_email');
    if (el.value.length == 0) {
        alert('Please enter your email address');
        return false;
    }
    var regex = /^[^@]+@[^@]+\.[a-z]{2,}$/i;
    if (el.value.search(regex) == -1) {
        alert('Invalid email address');
        return false;
    }
    return true;
}

function showDefinitions() {
    var el = $('definition_list');
    if (el) {
        showMask();
        el.inject($(document.body));
        var left = Math.max(0, (window.getSize().x - 820) / 2);
        var top = (window.getScroll().y + 30);
        el.setStyles({ 'left': left + 'px', 'top': top + 'px', 'display': 'block' });
    }    
}
function hideDefinitions() {
    hideMask();
    var el = $('definition_list');
    if (el) el.setStyle('display', 'none');
}

var _mask;
function showMask() {
    var size = window.getScrollSize();
    _mask = new Element('div', { 'styles': { 'position': 'absolute', 'z-index': '10', 'top': 0, 'left': 0, 'width': size.x, 'height': size.y, 'background-color': '#ccc', 'opacity': '0.6' }}).inject($(document.body));
}
function hideMask() {
    if (_mask) _mask.destroy();
}