Stopping Excel documents from loading inside IE

So IE is my target platform and I am using the following to send my stuff to excel

header( "Content-Type: application/vnd.ms-excel" );
header( "Content-disposition: attachement; filename=$report.xls" );
header( "Expires: 0" );
header( "Cache-Control: must-revalidate, post-check=0, pre-check=0" );
header( "Pragma: public" );

The problem is that we want report to when they click open (open in excel and not IE) It currently brings up the dialoge box that says open or save and when you click open it opens the document inside the web window and we lose the current page. Then they have to click the back button to a page that is expired and refresh. We are trying to avoid all that.

Can't you change the link that points to this script to include a target="_blank" tag?