PLZ HELP: convert mouse coordinate(2d) to 3D with using OpenGL

Hey people, i am russian and because bad speak english.
That’s my Q:

How me convert mouse coordinate(2D) on world(3D) with using OpenGL and matrices,
but with out GLU(gluUnproject, etc…). Please help. Me need source code with
commentary, good commentary!!! Need full source code… Thanks all, who help me

download the GLU source code from (you have to search for it)

Alternatively, you can look at Mesa sources of the equivalent functions.

I dot’t find GLU sorces on SGI!! mb give me link?

Me need this source!!!