how can i import a fbx material with a diffuse texure and a emissive texture?

Hi. I hava a media embed fbx model exported from 3ds max. The model is attached with a material with a diffuse texture and a emissive texture. After I dragged the fbx file into unity3d editor, I found there is a new material created, and the fbx diffuse texture is assigned to its Albedo texture which is correct. However, the emissive texture is missing. I looked up the manual, and figured out unity material's emission texture is just the emissive texture in fbx. So, why can't the emissive texture be assigned to the emission texture? How can i solve it without manual operation?