想要实现在写作时作用Enter来提交，作用Ctrl+S保存

    document.onkeydown=keyDownSearch;
   
    function keyDownSearch(e) { 
        // 兼容FF和IE和Opera 
        var theEvent = e || window.event; 
        var code = theEvent.keyCode || theEvent.which || theEvent.charCode; 
        if (code == 13) {  
            $("#todo-btn").trigger('click');
            return false; 
        } 
        return true; 
    }