Can't Install on Linux

[Huggybaby]

I am running Ubuntu 12.40 and received this message when I try to install, all help very much appreciated.

-Ubuntu:~/Installs/Magic$ ./forge.sh
Exception in thread "main" java.lang.UnsupportedClassVersionError: forge/view/Main : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
[i]<-deleted a bunch of stuff the forum claimed was "spammy"->[/i]
Could not find the main class: forge.view.Main. Program will exit.

Regards,

D.