LiveCode Forums.

Thanks you have so much ideas how I can realize it.
But I can not install an add on to firefox. There is no way to change the website, to install add ons to firefox or to install a application or something else at the computer.

Also I can not show you the source code to anyone because it is from my company with sensible data on it.
And I think I am not able to do this on my own because I do not understand javascript or jquery...

So I think the only possiblity is to NOT use Firefox as browser and to add the LC-Browser to my LC-App. So I can open the whole website in the LC-App.
So I need to figure out how to add some tab functionality and right click contect menu to open link in new tab or new window and so on.

I thank you very much for your help So much time you wastet.

No waste of time for me.
There are so much valuable hints from LCNeil, AndyP and FourthWorld I could also learn from (and some others will do), especially for that what you intend to do now.
Good luck.