Importing a 3d model (obj format) and texture from script in unity

I am using the ObjImporter from wiki to import 3d objects. I can also import textures on runtime. Here are some problems: 1. It creates the meshes only, how do i map the textures properly? 2. i am currently downloading obj files from turbosquid, some of the obj files are not being imported (can someone please tell me the possible reasons for this?) 3. Do i use a different obj importer? Thanks :)