c# - ASP.NET button server click event not firing after jquery e.preventdefault() fires -

i have web page use jquery ajax load data database fill drop down list. when jquery function runs, server events not fire.

jquery:

 $('#cmb_pdept').on('change', function (e) {                     e.preventdefault();                     var departmentid = $('#cmb_pdept :selected').val();                     if (departmentid == 0) {                         empcombo.empty();                         textbox.val("");                          return;                     }                     $.ajax({                         type: "post",                         cache: false,                         contenttype: "application/json; charset=utf-8",                         url: '/webservice/getemployeebydepid.asmx/getemployee',                         data: '{ "departmentid": "' + departmentid + '" }',                         datatype: 'json',                         success: function (data) {                             var data = $.parsejson(data.d)                             var options = $("#cmb_pemp");                             options.empty();                             (var = 0; < data.length ; i++) {                                 options.append("<option value='" + data[i]["employeeid"] + "'>" + data[i]["employeename"] + "</option>");                                }                             myevent();                         },                         error: function () { alert("error"); }                     });                 }); 

asp.net button control

<asp:button id="btn_pincrementsave" runat="server" text="save"              onclick="btn_pincrementsave_click" causesvalidation="false" /> 

the onclick event

protected void btn_pincrementsave_click(object sender, eventargs e) {         try         {             txbx_incrementamount.text = hid_basicsalary.value;         }         catch (exception ex)         {             utility.msg_error(this.master, ex.message);         }     } 

this event not fire. think due

 e.preventdefault(); 

when remove this, server-side event works properly.

to asp button add clientidmode="static" , check. weather asp:button id changed when source moved browser. may 1 reason. check id clicking view source in browser.