When/after I apply the following method of printing a PDF file:

DECLARE INTEGER ShellExecute IN "Shell32.dll" ;
    INTEGER hwnd, ;
    STRING lpVerb, ;
    STRING lpFile, ;
    STRING lpParameters, ;
    STRING lpDirectory, ;
    LONG nShowCmd
lcPDFfile = "c:\mydir\mydoc.pdf"
* Open PDF file
=Shellexecute(0,"Print", lcPDFfile, "","",0)

the Acrobat stays open. What parameters could I pass to the ShellExecute() to automatically close the Acrobat? (ideally I would prefer that user does not see it opening at all).

Also, just as a test, I specified non-existing .pdf file. But ShellExecute() didn't create a run-time error. Is it by design? How can I trap if user does not specify a valid location/name of a PDF file?

Thank you.