Not sure if trolling or...
The image you're uploading is "wl500g-clear-nvram.trx"
Guess what it does?
It writes empty data on your router. So I suggest you download yourself a real firmware image and flash it in the manner you've before.
You can download the oleg's based custom firmware : https://code.google.com/p/wl500g/downloads/list
You have a d version and a rtn version. The rtn version has a newer kernel, apart from that the only advantage is that it's still being updated.