jquery ajax Function undefined -

returning response function every time end undefined function!!

var result = checkusers();(result undefined)   function checkuser() {      var empname = $("#txtname").val();      $.ajax({                 type: "post",         url: location.pathname + "/userexist",         data: "{name:'" + empname + "'}",         contenttype: "application/json; charset=utf-8",         datatype: "jsondata",         async: "true",         success: function (response) {             console.log(response.d);             var obj = eval('(' + response.d + ')');             return obj;         },         error: function (response) {             alert(response.status + ' ' + response.statustext);                  }     }); } 

i calling function

var result = checkuser(); if(result== false){      //do } else{     //do } 

i have struggling past 1 day!! read in section because of 'ajax asynchronous' . how handle it??

you're better off passing callback function checkuser

function checkuser(callback) {      var empname = $("#txtname").val();      $.ajax({                 type: "post",         url: location.pathname + "/userexist",         data: "{name:'" + empname + "'}",         contenttype: "application/json; charset=utf-8",         datatype: "jsondata",         async: "true",         success: function (response) {             console.log(response.d);             var obj = eval('(' + response.d + ')');             callback(obj);         },         error: function (response) {             alert(response.status + ' ' + response.statustext);             callback(null);                  }     }); } 

you call function so

checkuser(function (res) {     if (res === null) {        //false     } else {        //true     } });