function createEl(tagName, className) {
    return $(document.createElement(tagName)).addClass(className);
}
String.format = function (src) {
    if (arguments.length == 0) return null;
    var args = Array.prototype.slice.call(arguments, 1);
    return src.replace(/\{(\d+)\}/g, function (m, i) {
        return args[i];
    });
};