onChange event is not working for input type "Select "

In 3.0 version I have used the “onChange” event for Dhtmlxform input type “select”.It works fine there. Now I want to move to Dhtmlx_pro_full 3.5 version,here the “onChange” event is not firing for “select” types…,it is firing for “input” types only.Is there any solution to fix it…Please relay me…

here is my code :

JSP Page
        var main_layout = new dhtmlXLayoutObject("layoutDiv", '1C');

        var a = main_layout.cells('a');
        var str = [
                { type:"settings" , labelWidth:80, inputWidth:250, position:"absolute"  },
                { type:"select" , name:"form_select_1", label:"SelectBox", labelWidth:250, labelLeft:352, labelTop:17, inputLeft:352, inputTop:38, options:[
                { value:"option_1", text:"option_1" },
                { value:"option_2", text:"option_2" },
                { value:"option_3", text:"option_3" }
                        ] },
               { type:"input" , name:"form_input_1", label:"InputBox", labelWidth:250, inputWidth:250, labelLeft:379, labelTop:92, inputLeft:379, inputTop:113  },
               { type:"settings" , labelWidth:80, inputWidth:250  }

        var form_1 = a.attachForm(str);

        form_1.attachEvent('onChange', function(id, value){


There is no issue in the latest 3.6 version: see attached demo
form_3.6.rar (511 KB)