I have a javascript. I did not understand the language.
here is the link of the script
http://www.unitconversion.org/converter3/converter3.js

Can anybody explain me the script. thank you

This is javascript alright. It looks like the creator of the script has encrypted it. This can be done with one of several available javascript encryptors online.

If you're looking for a script for a specific function, let us know what the function if and we might be able to help out.

The first part of the script looks like the function to decrypt the rest of the script. Although everything is a bit obfuscated, you can replace eval with document.write (at the end of the script) to view the original javascript.

But again, it's obfuscated so it's still difficult to understand.