Enable/disable the properties of components

hi, my problem is i want to enable or disable the properties of components,, for example Mesh Renderer is having Cast Shadows and Receive Shadows, so i want to enable or disable them,, please help..

renderer.castShadows = false;

the docs have all of the components and their properties. if you cannot find one simply ask! here are the properties of the renderer:

http://unity3d.com/support/documentation/ScriptReference/Renderer.html

To get the component you can call GetComponent() or make the component a public variable and drag the component in the inspector slot.