var dataGet;
    var dataSend = "airfrom='SEOUL'&airto='Yuzhny'";
    var xmlhttp = new XMLHttpRequest();
    xmlhttp.open('POST','http://ems-falcon/getflights.php',false);
    xmlhttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
    xmlhttp.onreadystatechange =function(){
	  if ( xmlhttp.readyState == 4 )   {
          if ( xmlhttp.status == 200 )   {
                	dataGet=eval( "(" + xmlhttp.responseText + ")" );
  		  }
		else alert( "There was a problem with the URL." );
        http_request = null;
       }
    }; 
	xmlhttp.send(dataSend);
   return dataGet;
}

<?php 
//$entry = array();
$entry = array ("fliht" => array (),"Air_from"  => array (),"Air_fromCod"  => array (),"Air_to"  => array (),"Air_toCod"  => array ());
if (isset($_POST['airfrom']) && isset($_POST['airto'])){
     include ("db.php");
     $tsql = "DECLARE @rn_value int EXEC	@rn_value = getflightsTable @airfrom = ".$_POST['airfrom'].",@airto = ".$_POST['airto']." SELECT 'Return Value' = @rn_value";
   	 $stmt = sqlsrv_query($conn,$tsql);
	if( $stmt === false) {
       echo "Error in query preparation/execution.\n";   die( print_r( sqlsrv_errors(), true));
    }
	while($row = sqlsrv_fetch_array( $stmt, SQLSRV_FETCH_ASSOC)){
	 	 $entry["fliht"]=$row['fliht'];
		 $entry["Air_from"] =$row['Air_from'];
		 $entry["Air_fromCod"] =$row['Air_fromCod'];
		 $entry["Air_to"] =$row['Air_to'];
		 $entry["Air_toCod"] =$row['Air_toCod'];
		 
	}
	sqlsrv_free_stmt( $stmt);
    sqlsrv_close( $conn);
  }
else {
 $entry["fliht"] = "Ошибка";
}
echo json_encode($entry);
?>

ALTER PROCEDURE [dbo].[getflightsTable]
	@airfrom nvarchar(50),
        @airto nvarchar(50)
AS
BEGIN
     SELECT     flight.ID, flight.flight, airports.[Airport name] AS Air_from, airports.[Airport Code] AS Air_fromCod, airports_1.[Airport name] AS Air_to, airports_1.[Airport Code] AS Air_toCod
     FROM         flight INNER JOIN
                      airports ON flight.air_from_id = airports.ID INNER JOIN
                      airports AS airports_1 ON flight.air_to_id = airports_1.ID
     WHERE     (airports.[Airport name] = @airfrom) AND (airports_1.[Airport name] = @airto)
END

if( $stmt === false) {
       echo "Error in query preparation/execution.\n";   die( print_r( sqlsrv_errors(), true));

for (obj in dataGet)
	{
		for (j=0; j<dataGet[obj].length; j++){
			alert(dataGet[obj][j]);
		}
	}