javascript - Call an event from another element -

i have button a

onclick = "alert(1);" 

and button b.

how do, when click on button b , should call event on button a ?

click b -> eventb -> eventa

html:

<button id="buttona"> button </button> <button id="buttonb"> button b </button> 

javascript:

var = g('buttona'),     b = g('buttonb');  function g(s) { return document.getelementbyid(s); }  a.onclick = function() {     alert('button clicked!'); };  b.onclick = function() {     alert('button b clicked!');     a.click(); } 

live demo: http://jsfiddle.net/tapwr/1/

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update:

if button b inside iframe use top object reference window object of "parent" page. iframe code so:

var b = document.getelementbyid('buttonb');  b.onclick = function() {     alert('button b clicked!');     top.document.getelementbyid('buttona').click(); }