Acropdf: close AcroRd32.exe

Hi,
I use this code to print a pdf file:

function OpenAndPrintPDF(pdfUrl)
{
PDF.LoadFile(pdfUrl);
PDF.SRC=pdfUrl;
PDF.PrintAll();
}

and it works.
Now I have two PDF and i want to print them on two different printers, so I create two page like above and i make a vbscript to change the default printer on body onload event. The script works well and changes the default printer, but the acropdf object prints always on the first printer.
I see Acro32rd.exe stays on task manager also when I close the page, perhaps the problem is here.
Can anyone help me? Can I close Acro32rd.exe process? Is there any method?
Thank you.