สอบถามเรื่อง font ของ fpdf ครับ จะนำ THSarabun มาใช้ครับ

<?
ob_start();
require_once('config.php');
$monty=array("--เลือก--","มกราคม","กุมภาพันธ์","มีนาคม","เมษายน","พฤษภาคม","มิถุนายน","กรกฎาคม","สิงหาคม","กันยายน","ตุลาคม","พฤศจิกายน","ธันวาคม");
$sql_slip="SELECT * FROM salary_horizontal WHERE idcard='".$_GET['idcard']."' and year_data='".$_GET['year_data']."' and month_data='".$_GET['month_data']."'";
$query_slip=mysql_query($sql_slip);
$result_slip=mysql_fetch_array($query_slip);
require('fpdf/fpdf.php');
class PDF extends FPDF
{
var $B;
var $I;
var $U;
var $HREF;

function PDF($orientation='L',$unit='mm',$format='A4')
{
	//Call parent constructor
	$this->FPDF($orientation,$unit,$format);
	//Initialization
	$this->B=0;
	$this->I=0;
	$this->U=0;
	$this->HREF='';
}

function WriteHTML($html)
{
	//HTML parser
	$html=str_replace("\n",' ',$html);
	$a=preg_split('/<(.*)>/U',$html,-1,PREG_SPLIT_DELIM_CAPTURE);
	foreach($a as $i=>$e)
	{
		if($i%2==0)
		{
			//Text
			if($this->HREF)
				$this->PutLink($this->HREF,$e);
			else
				$this->Write(5,$e);
		}
		else
		{
			//Tag
			if($e{0}=='/')
				$this->CloseTag(strtoupper(substr($e,1)));
			else
			{
				//Extract attributes
				$a2=explode(' ',$e);
				$tag=strtoupper(array_shift($a2));
				$attr=array();
				foreach($a2 as $v)
				{
					if(preg_match('/([^=]*)=["\']?([^"\']*)/',$v,$a3))
						$attr[strtoupper($a3[1])]=$a3[2];
				}
				$this->OpenTag($tag,$attr);
			}
		}
	}
}

function OpenTag($tag,$attr)
{
	//Opening tag
	if($tag=='B' or $tag=='I' or $tag=='U')
		$this->SetStyle($tag,true);
	if($tag=='A')
		$this->HREF=$attr['HREF'];
	if($tag=='BR')
		$this->Ln(5);
}

function CloseTag($tag)
{
	//Closing tag
	if($tag=='B' or $tag=='I' or $tag=='U')
		$this->SetStyle($tag,false);
	if($tag=='A')
		$this->HREF='';
}

function SetStyle($tag,$enable)
{
	//Modify style and select corresponding font
	$this->$tag+=($enable ? 1 : -1);
	$style='';
	foreach(array('B','I','U') as $s)
		if($this->$s>0)
			$style.=$s;
	$this->SetFont('',$style);
}

function PutLink($URL,$txt)
{
	//Put a hyperlink
	$this->SetTextColor(0,0,255);
	$this->SetStyle('U',true);
	$this->Write(5,$txt,$URL);
	$this->SetStyle('U',false);
	$this->SetTextColor(0);
}
}
?>
<table width="1008" border="0" cellspacing="0" cellpadding="0">
  <tr>
    <td><table width="100%" border="0" align="center" cellpadding="0" cellspacing="0">
      <tr>
        <td colspan="3" align="center" class="tb_n"><strong>ใบรับรองการจ่ายเงินเดือนและเงินอื่น ประจำเดือน 
          <?=$monty[$result_slip["month_data"]]?>
ปี พ.ศ.
<?=$result_slip["year_data"];?>
        </strong></td>
        </tr>
      <tr>
        <td width="32%" class="tb_n"><strong>ชื่อ-นามสกุล</strong> <span style="font-size:12.0pt;font-family:
  &quot;TH SarabunPSK&quot;,&quot;sans-serif&quot;;color:black">
          <?=$result_slip['fname']?>
          <?=$result_slip['lname']?>
        </span></td>
        <td width="36%" class="tb_n"><strong>กรม</strong> <span style="font-size:12.0pt;font-family:&quot;TH SarabunPSK&quot;,&quot;sans-serif&quot;;
  color:black">
          <?=$result_slip['gov_part']?>
        </span></td>
        <td width="32%" class="tb_n"><strong>สำนัก/กอง/ศูนย์</strong> <span style="font-size:12.0pt;font-family:&quot;TH SarabunPSK&quot;,&quot;sans-serif&quot;;
  color:black">
          <?=$result_slip['gov_name']?>
        </span></td>
      </tr>
      <tr>
        <td class="tb_n"><strong>โอนเงินเข้า </strong><?=$result_slip['bank_name']?></td>
        <td class="tb_n"><strong>เลขที่บัญชี </strong><?=$result_slip['bank_book_bank_no']?></td>
        <td class="tb_n">&nbsp;</td>
      </tr>
      <tr>
        <td class="tb_n"><strong>รายการายรับ</strong></td>
        <td>&nbsp;</td>
        <td>&nbsp;</td>
      </tr>
    </table></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td><table width="100%" border="0" align="center" cellpadding="0" cellspacing="0">
      <tr>
        <td class="tb_n"><strong>รายการายจ่าย</strong></td>
      </tr>
    </table></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
  </tr>
</table>

<?
$html=ob_get_contents();

$pdf=new PDF();
$pdf->AddPage();
$pdf->SetLink($link);
//$pdf->Image('logo.png',10,12,30,0,'','https://www.thaicreate.com');
$pdf->AddFont('THSarabun','','THSarabun.php');
$pdf->SetLeftMargin(45);
$pdf->SetFontSize(14);
$pdf->WriteHTML($html);

$pdf->Output("MyPDF/MyPDF.pdf");
?>
<a href="MyPDF/MyPDF.pdf">LINK </a>