MonoDevelop Error [NameSpace name UnityEngine could not be found]

In all of my scripts this is an error.I tried reinstalling and doing some other stuff and even updating ,but none helped.....

What can I do to fix this issue?? It worked all fine,until I converted 1 line of javascript code and copy pasted the C# result including the comment into my script.... Now all of my scripts are failing.

The error shows to be in another file.I just have no idea. Even I create a new C# script and just try to compile it/debug it or how ever you call it,it fails.Not even 1 script works now...

This is the link I used: http://www.m2h.nl/files/js_to_c.php I converted a code of a multiplayer sync variable... To sync couple of variable with client and server such as transform,stats and so on...