สอบถามเรื่อง ค้นหาข้อมูลสองตารางไม่ยอมเเสดงค่าออกมาครับ

while($obResult = mysql_fetch_array($objQuery))
{
	$resultArray[] = $obResult;
}

$strKeyword = $_POST["txtKeyword"];

$strSQL = "SELECT * FROM student_sub,memberscan WHERE student_sub.Idstudent=memberscan.student_sub AND  Idstudent LIKE '%".$strKeyword."%'  ";

<?php
	$objConnect = mysql_connect("localhost","web84u1","qr456");
	$objDB = mysql_select_db("web84db1");
	mysql_query("SET NAMES UTF8");
	//("SET NAMES 'utf8' COLLATE 'utf8_general_ci';");

	
	// $_POST["txtKeyword"] = "a"; // for Sample

	$strKeyword = $_POST["txtKeyword"];
	$strSQL = "SELECT * FROM student_sub,memberscan WHERE student_sub.Idstudent=memberscan.student_sub AND  Idstudent LIKE '%".$strKeyword."%'  ";
	

	$objQuery = mysql_query($strSQL);
	//$intNumField = mysql_num_fields($objQuery);
	$resultArray = array();
	//while($obResult = mysql_fetch_array($objQuery))
	while($obResult = mysql_fetch_assoc($objQuery))
	{
/*
		$arrCol = array();
		for($i=0;$i<$intNumField;$i++)
		{
			$arrCol[mysql_field_name($objQuery,$i)] = $obResult[$i];
		}
		array_push($resultArray,$arrCol);
*/
		array_push($resultArray,$obResult);
	}
	
	mysql_close($objConnect);
	
	echo json_encode($resultArray);
?>