I used flush() function in infinite loop in my php page, it echoes a text each second. when i open the page in browser it works! but when i load it via jquery ajax it doesn't response!
php page
    <?php
if (ob_get_level() == 0) ob_start();
for ($i = 0; true/*$i<10*/; $i++){
        echo "<br> Line to show. $i";
        echo str_pad('',4096)."\n";    
        ob_flush();
        flush();
        sleep(1);
}
ob_end_flush();
?>
jquery code
$.ajax({
  url: 'res.php',
  beforeSend: function(  ) {
    $('#mydiv').html('loading...');
  },
  success: function( data ) {
      $('#mydiv').html(  data );
  }
});
 
     
     
    