raster map display problem

Hello,

I installed grass4.2 in linux RedHat 5.2. I try to convert a tiff file
to a grass raster map and display it. I use the commands:
  r.in.tiff
  d.rast
While it just displayed a white sheet on the graphic screen. I do not
know the convertion is not correct or the raster map display is not
right. What should I do?

Thanks for any response.

Weili