Problem with premake

When I tried to generate the make file, I got some errors.
My Command is:

```
D:\GitRepo\clink\clink>lua premake4.lua gmake
```

But I got this error message:

```
lua: premake4.lua:56: attempt to index global 'premake' (a nil value)
stack traceback:
        premake4.lua:56: in main chunk
        [C]: ?
```

I have installed `premake4`. 

What is wrong here?

regards,
srik
