Creating excel sheets through php with an image

The head like this:
header("Content-Type: application/vnd.ms-excel");
header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("content-disposition: attachment;filename=monthly_report.xls");
The Content:
$sheet->mergeCells(0,0,2,14);
$titleFormat =& $xls->addFormat();
$titleFormat->setSize('20');
$titleFormat->setColor('navy');
$titleFormat->setBottom(2);
$titleFormat->setBottomColor('navy');
$titleFormat->setAlign('merge');
$sheet->write(0,0,"Monthly Report",$titleFormat);
But,I used pear display excel data.