I use GETPRINTER() for a print dialog then this function returns am empty string in case a user did not select any printer to print to. Thus my invoice will not be updated.

I have one local printer and one netword printer, When I want to print my invoice to the network printer, It always goes to the local printer and never go to netword. Sometime never print.......Why
My coding as belows:-

cPrinter = getprinter()
if !empty(cPrinter)
select setup
do whil !rlock()
endd
stor incred(invoiceno) to tt_invoice
unlock
else
wait wind 'No Printer Chosen'
endi

But If I using this command ' report form reportname to printer prompt nonconsole', It has no problem as all either to print to network printer or local printer. But the point is I cannot detect the user to click on OK button or Cancel Button?