.click()
is not standard. You need to create an event and dispatch it:
function click(el){
var ev = document.createEvent("MouseEvent");
ev.initMouseEvent(
"click",
true /* bubble */, true /* cancelable */,
window, null,
0, 0, 0, 0, /* coordinates */
false, false, false, false, /* modifier keys */
0 /*left*/, null
);
el.dispatchEvent(ev);
}