multiple select without need for command key

no command multiple select

var selected = [];
$(document).ready(function(){
    $("#selected option:selected").each(function(i){
         selected.push($(this).val());
    });
    $("#selected").click(function(e){
        if($.inArray(e.target.value, selected) > -1){
            selected.splice($.inArray(e.target.value, selected),1);
        }else{
            selected.push(e.target.value);         
        }     
        $(this).val(selected);
    });         
});​