Last nite I flashed my dsl router with a firmware off of d-links website http://tsd.dlink.com.tw/downloads2008detailgo.asp I used the DSL-2540U T1 FW IM_1.00 firmware. I flashed the router through its web interface. it restarted and all that happens now is that the dsl stays grey and if I plug an Ethernet cable into any of the ports they light up. Previously the power and status lights would come on.

Can anyone with the know how to fix this router please let me know as I cannot figure out what to do from here?

If you flashed over wireless probably you bricked the router.
You can see in manual if there is a recovery solution.

But remember, never flash over wireless always over Ethernet.

DSL-2540U does not have wireless..

It comes in several different versions and simply wrong firmware can very well brick it..

When you choose the official firmware, first you should check the sticker underneath the device, "H/W Ver."  It may be C1, C2, T1 etc..
Choose the firmware that fits accordingly..