Why doesnt't this code work?

Code:
D3DGAMMARAMP d3dgr;

float fTemp=0;

for(int R=0;R <= 255;R++)
{
	fTemp = ( R / 255 ) * 65535;
	d3dgr.red[R] = (WORD)fTemp;
	d3dgr.green[R] = (WORD)fTemp;
	d3dgr.blue[R] = (WORD)fTemp;
}

g_pDevice->SetGammaRamp(D3DSGR_NO_CALIBRATION,&d3dgr);
Something that is in the black scale will turn completly black, and those who are in the red scale will become completely red.