title: $.fn.func do not return me string
body: <p>this function is work but when call that value of return is undifined </p>
  
  <pre><code>            $.fn.check=function (fieldName,fieldValue) {
          $val=$(this).val();
          $.post('proccess.php',{check:'check',fieldName:fieldName,fieldValue:fieldValue},
  function (res) {
              if(res=='true')
              {
                  return 'true'; // this line is work
              }
              else if(res=='false')
              {
                  return 'false';  // this line is work
              }
          })
      };
  
      //calling function
      $('#register input[name=name]').focusout(
          function () {
              var checked=$(this).check('name',$(this).val());
              //but here  value of checked is undifined
              if(checked==true)
              {
                  $(this).next('.checked').text('ok');
              }
              else if(checked==false)
              {
                  $(this).next('.checked').text('not ok');
              }
          }
      )
  </code></pre>
  
  <p>my problem is with $.fn. function  dont return string data 
  my country language is not english please dont dislike my post :(</p>