Lighting and transparent objects

When I create a transparent object (any object), I want to have a light shine through it and have the shadow on the ground become change depending on the alpha and colour of the object, all I get is straight black. I have tried various things but nothing seems to work. Someone help me please.

also how would I make blurry shadows ie realistic shadows

Just set TraShadow on the material of the objects receiving shadow.

For soft shadows use area lamps of spotlights with blurry shadows.

The blender user manual:

duh slaps forehead, I didn’t put it on the object receiving shadows. I’ve only been using blender for a couple of months and am learning more every day :P.

a BIG THANK YOU to cipix