I have found a source code for copying to clipboard that is fitable for

IE:

"http://jsfiddle.net/azgugmjb/7/light/" "https://jsfiddle.net/jsLfnnvy/12/"

and

Chrome:

"Copy to Clipboard using Chrome only"

But not for Firefox.

Do you know any sourcecode for Firefox in relation to copying to clipboard?

I DO NOT want to use an extension application or similiar. Sourcecode only!

Thanks!