submit using enter key

[LUCERO,DENNIS (HP-Boise,ex1)]

I have a form, that cannot have a submit button (unless there is some way to
have it be hidden)
How to I get that form to submit when the enter key is pressed.
 
thanks
 
We come from the land of the ice and snow
With the midnight sun, where the hot springs glow
The hammer of the gods, will drive our ships to new lands
Fight the horde, Sing and cry
Valhalla I am coming