[รบกวนถาม] เรื่องการเรียกใช้ session ของ jpgraph ครับ (PHP, MySQL)

<?php
session_start();
include ("src/jpgraph.php");
include ("src/jpgraph_pie.php");

// ติดต่อ ฐานข้อมูล เลือกข้อมูลขึ้นมาเพื่อแสดงกราฟ
$objConnect = mysql_connect("localhost","benzoasis","nazeoasis009") or die("Error Connect to Database");
$objDB = mysql_select_db("register");
$checkge = $_REQUEST['name_ge'];
$checkgroup = $_REQUEST['name_group'];
$id = $_REQUEST['cha_info'];
mysql_query("SET NAMES UTF8");
$strSQL = " select * from list_stu where add_stu = '$id' and group_ge = '$checkgroup'";
$objQuery = mysql_query($strSQL) or die ("Error Query [".$strSQL."]");

$data=array();
while($objResult = mysql_fetch_array($objQuery))
{
$data[1] = $objResult["in_check"];
$data[2] = $objResult["not_check"];
}

$labels=array();
{
$labels[1] = iconv('TIS-620', 'UTF-8', Check);
$labels[2] = iconv('TIS-620', 'UTF-8', Not_Check);
}

$graph = new PieGraph(390,300,"auto");
$graph->SetShadow();

$graph->title->Set("จำนวนการเข้าเรียนของนักศึกษา");
$graph->title->SetFont(FF_ANGSA,FS_BOLD,20);

$p1 = new PiePlot($data);
$p1->SetColor('[email protected]');
$p1->SetSliceColors(array('gold', 'darkgreen'));

$p1->SetCenter(0.4);
$p1->SetValueType(PIE_VALUE_ABS);

$p1->SetLegends($labels);
$p1->value->SetFormat('%d');
$p1->value->SetFont(FF_ANGSA,FS_BOLD,15);


$graph->Add($p1);
$graph->Stroke();

?>