javascript - $.ajax submiting a form, sometimes get success and sometimes error -

i have simple log-in form passed php through $.ajax function. problem on localhost $.ajax function result success , error. of time when i'm getting success when i'm using chrome debugger. when checked file on server got error result $.ajax.

thanks in advance..

form code:

<form method="post" action="">         <h3>login</h3>         <label>user name:<input type="text" name="uname" id="uname"></label>         <br>         <label>password:<input type="password" name="pass" id="pass"></label>         <br>         <button type="submit" id="submit">login</button>     </form> 

$.ajax code

  $("#submit").click(function(){                 $.ajax({                     cache: false,                     url: 'php/login.php',                     type: 'post',                     datatype: 'json',                     data: {                         uname: $('#uname').val(),                         pass: $('#pass').val()                     },                      success: function (data) {                         cookies.set('uid', data[0].uid);                         alert("test");                     },                     error: function (xhr, status) {                         alert("sorry, there problem!");                     },                 });             }) 

php code

header("access-control-allow-origin: *"); header("content-type: application/json; charset=utf-8");  require_once 'config.php'; $conn = mysqli_connect($hn, $un, $pw, $db); if ($conn->connect_error) die($conn->connect_error);  $uname=mysql_real_escape_string($_post['uname']); $pass=md5(mysql_real_escape_string($_post['pass']));  $result = $conn->query("select * users uname '$uname' , upass '$pass'");           $outp = "[";     while($rs = $result->fetch_array(mysqli_assoc)) {             $outp .= '{"uid":"'.$rs["uid"].'"}';         }         $outp .="]";   $conn->close(); echo($outp); 

your form still trying submit normal way because aren't intercepting it.

add id form.

<form id="myform" method="post" action="">

change code below , give shot. we're doing intercepting form submit , preventing default action.

$("#myform").submit(function(event){     $.ajax({         cache: false,         url: 'php/login.php',         type: 'post',         datatype: 'json',         data: {             uname: $('#uname').val(),             pass: $('#pass').val()         },          success: function (data) {             cookies.set('uid', data[0].uid);             alert("test");         },         error: function (xhr, status) {             alert("sorry, there problem!");         },     });     event.preventdefault(); });