PrintDlg function failing with PD_RETURNDEFAULT

Hi,
I am calling PrintDlg function with PD_RETURNDEFAULT flag set. ( I
dont want the Printer Dialog Box to be seen )
It fails. I have set the hDevNames and hDevMode to be NULL before
calling the function PrinTDlg.

For getting the error code I had called CommDlgExtendedError().
The error code returned was PDERR_NODEFAULTPRN.
Error code implies that the default printer not found.But the default
printer is configured for my machine. still why does it throw this
error.

Had tried PrintDlgEx function. Even that failed with the same error
code PDERR_NODEFAULTPRN.

Can anyone help me with this.
TIA
Guddu