VS 2010 Deterime the Print Copy no while printing

I am using an PrintDocument to draw an invoice to be printed , i wish to give an option to print "Duplciate Copy" on the second and consecutive copies of the invoice.

I have noticed that if "No of Copies" are given more than one in the PrintDialog, then the Print event of the PrintDocument is called only once any no. of copies.

Please help me in determining the copy no