whats prevent shadows from coming

I am not able to produce shadows in unity 3d pro. I have tried with both hard and soft shadows. But not able to see shadows .I also want to produce realtime shadows and detect shadows.
whats preventing shadows from coming.

I have attached the scence with my question. 1401-shadows.zip (3.99 KB)

Do not use the built in default diffuse, it has no shadow support apparently.
Create a material, diffuse shader, optionally assign a color.

Shadow should now appear at least in game view.

Click on your light, and make sure you set it to have shadows.
Also check your quality settings. Project Settings → Quality.
You may be on an editor quality setting that has shadows disabled.