Direct X gamma ramps

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);

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Something that is in the black scale will turn completly black, and those who are in the red scale will become completely red.