attr('selected', true); more than two times don't selected, the version of jQuery after 1.8 : attr('selected', true); more than two times don't selected, the version of jQuery after 1.8       

[simple here - jsfiddle.net/fWLJ9/236/][1] 
[1]: http://jsfiddle.net/fWLJ9/236/

<!-- begin snippet: js hide: false console: true -->

<!-- language: lang-js -->

    $(document).on("click",".edit", function(){
    $("#editor").find("select").prop('selectedIndex',0);
    $("#editor").find("#whour option[value='"+this.id+"']").attr('selected', true);

    });

<!-- language: lang-html -->

    <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.0/jquery.min.js"></script>
    <div id="editor">
    					<select id="whour" name="duration[hr]"> 
    					<option value="0">——</option>
    					<option value="1">1 h.</option><option value="2">2 h.</option><option value="3">3 h.</option><option value="4">4 h.</option><option value="5">5 h.</option><option value="6">6 h.</option><option value="7">7 h.</option><option value="8">8 h.</option><option value="9">9 h.</option><option value="10">10 h.</option>					
    					</select>
    					</div>
        
    <button id="2" class="edit">
    2h
    </button>

    <button id="3" class="edit">
    3h
    </button>
    <button id="4" class="edit">
    4h
    </button>

    <button id="5" class="edit">
    5h
    </button>

<!-- end snippet -->


there is a decision?