Lambert's Projection and PHP

Hello, I'm working with a system that draws a map from certain information. Lambert's projection seems to suit well to our needs. Now I should generate a function that converts the lat/lon coordinates to the x,y coordinates using the Lambert's projection. As I couldn't find any ready-to-use script, I decided to write it from scratch... Well, no results at the moment. ;) I found a formula explaining the projection at http://mathworld.wolfram.com/LambertConformalConicProjection.html . Unfortunately there is no explanation that what units x and y are, so drawing them or further convertion is impossible. Now I would appreciate your help with this case. Any help is appreciated! Scripts, formulaes and other stuff give valuable help for the project. Thank you! Ville Mattila Ikaalinen, Finland