ติดปัญหา Error โค้ด เกี่ยวกับการใช้ DOMDocument::load() รบกวนช่วยดูให้หน่อยได้มั๊ยคะ? *Import Excel

<?php
require_once('core.php');

if($_FILES['file']['tmp_name']!='')
{
	//======Get data from Excel======================//        
	$dom = DOMDocument::load( $_FILES['file']['tmp_name'] ); 
	$rows = $dom->getElementsByTagName( 'Row' ); 
	$row = 0; 

	foreach ($rows as $temp)
	{
		$col = 0; 
		if($row==0)
		{ 
			$row++; continue; 
		} 
		$cells = $temp->getElementsByTagName('Cell'); 

		foreach( $cells as $cell )
		{ 
			if($col==0) $data1 = $cell->nodeValue; 
			if($col==1) $data2 = $cell->nodeValue; 
			if($col==2) $data3 = $cell->nodeValue; 
			//if($col==3) $data4 = $cell->nodeValue; 
			//if($col==4) $data5 = $cell->nodeValue; 
			$col++; 
		}
	//======End Get data from Excel======================//

		$data1 = trim($data1);
		$chk_sql = "select * from busunit where BU_THAINAME = '".$data1."' ";
		$chk_result = $db->select_query($chk_sql);
		$chk_row = $db->rows($chk_result);
		if($chk_row==0)
		{
			//==================Insert To DB ====================================//
			$sql = " INSERT INTO busunit (";
			$sql .= " BU_THAINAME, ";
			$sql .= " BU_ENGNAME ";
			$sql .= " STATUS, ";
			//$sql .= " field_4, ";
			//$sql .= " field_5 ";
			$sql .= " ) VALUES ( ";
			$sql .= " '$data1', ";
			$sql .= " '$data2' ";
			$sql .= " '$data3', ";
			//$sql .= " '$data4', ";
			//$sql .= " '$data5' ";
			$sql .= " ) ";
			
			if($data1!='')
			{
				$db->select_query($sql) or die(mysql_error()); 
			}
			//==================End Insert To DB ====================================//
		}

		$row++;  
	}

	$sql_db = "select * from busunit";
	$result = $db->select_query($sql_db);
	$i = 0;
	while($row = $db->fetch($result))
	{
		$i++;
		echo $i." : ".$row[BU_THAINAME]."<br/>";
	}

	$db->closedb();
}
?>