Raster Position

Hi,
I am getting a little frustrated. When I change the size of the window in my application the raster position moves so when a draw to the screen (glDrawPixels)
it draws them in the wrong place i.e. not at the bottom left of the window which it does before any window resizing. How can I keep its position in the lower left corner ?
Any help would be welcom
Thanks
Paul

Try this:

RECT rect;
int heightClient;
int widthClient;

GetClientRect(hwnd, &rect);
widthClient  = rect.right - rect.left;
heightClient = rect.bottom - rect.top;

glViewport(0, 0, widthClient, heightClient);
glMatrixMode(GL_PROJECTION);
glPushMatrix();
// Setup viewport aligned projection        
glLoadIdentity();
glOrtho(0.0, (GLdouble) widthClient, 0.0, (GLdouble) heightClient, -1.0, 1.0); 

glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glRasterPos2i(0, 0);
glDrawPixels(widthClient, heightClient, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glMatrixMode(GL_MODELVIEW);
glPopMatrix();