defer 1

(function(global){

var $ = global.jQuery || global,
    D = Date,
    now = D.now || function() {
        return (new D).getTime();
    };

// if once is true, fn will be executed only once if called more then one times during the time in delay.
// if once is not defined or false, fn will be executed periodically, period is delay.
$.defer = function(fn, delay, once) {

    if (!delay || typeof delay === 'boolean') {
        once = delay;
        delay = 100;
    }

    var ret,
        lasttime, currenttime,
        enabled = true,
        wrapper, enable;

    if (once) {
        wrapper = function() {
            currenttime = now();
            
            if (!lasttime || currenttime - lasttime  > delay) {
                ret = fn.apply(this, arguments);
            }
            
            lasttime = currenttime;
    
            return ret;
        };
    } else {
        enable = function() {
            enabled = true;
        };
        
        wrapper = function() {
        
            if (enabled) {
                ret = fn.apply(this, arguments);
                enabled = false;
                setTimeout(enable, delay);
            }
            
            return ret;
        };    
    }



    // Set the guid of unique handler to the same of original handler, so it can be removed
    if ( $.guid ) {
        wrapper.guid = fn.guid = fn.guid || $.guid++;
    }
    
    return wrapper;
};

}(this));