how to imitate a click in javascript code example

Example 1: javascript perform click

function eventFire(el, etype){
  if (el.fireEvent) {
    el.fireEvent('on' + etype);
  } else {
    var evObj = document.createEvent('Events');
    evObj.initEvent(etype, true, false);
    el.dispatchEvent(evObj);
  }
}

Example 2: javascript perform click

eventFire(document.getElementById('mytest1'), 'click');