Ext.TaskMgr.start

/**
 * @class Ext.util.TaskRunner
 * Provides the ability to execute one or more arbitrary tasks in a multithreaded
 * manner.  Generally, you can use the singleton {@link Ext.TaskMgr} instead, but
 * if needed, you can create separate instances of TaskRunner.  Any number of
 * separate tasks can be started at any time and will run independently of each
 * other. Example usage:
 * 

// Start a simple clock task that updates a div once per second
var updateClock = function(){
    Ext.fly('clock').update(new Date().format('g:i:s A'));
} 
var task = {
    run: updateClock,
    interval: 1000 //1 second
}
var runner = new Ext.util.TaskRunner();
runner.start(task);

// equivalent using TaskMgr
Ext.TaskMgr.start({
    run: updateClock,
    interval: 1000
});