Here is the code I use to create a window and preview a report.

*** Issuing a REPORT FORM (formname) PREVIEW with the Status Bar set ON causes Visual FoxPro
*** 	to leak one memory handle each time you close the Preview window.
SET STATUS BAR OFF

lcWindowTitle = 'Previewing Report: ' + lcReportDescription

DEFINE WINDOW PreviewReport FROM 0,0 TO SROWS() * 0.93, SCOLS() ;
      TITLE (lcWindowTitle) FLOAT NOCLOSE GROW SYSTEM NOMINIMIZE

REPORT FORM (lcReportName) NOCONSOLE PREVIEW WINDOW PreviewReport 

HIDE WINDOW PreviewReport
RELEASE WINDOW PreviewReport

SET STATUS BAR ON

>HI,
>
>Every time i call a report with PREVIEW SCREEN,
>the PREVIEW SCREEN is small.
>I need to make it full screen by mouse.
>
>How can i default the size of PREVIEW SCREEN.