when i try to use to use server shortcut,my browsers says that i need some software to join to that server,but i have lfs. is this a website bug or something???

Normally it's installed with LFS only when you tick one of those options in the installer. I believe it only adds one registry key to tie join link with LFS app.

Instead of installing LFS again go here:
http://www.lfs.net/?page=addons

and download LFS Associations Setup, run it then tie it to your desired LFS installation. It does the same thing as complete installation but without replacing any files, only registry update. Join link should work now.

And I had awkwardly been searching for a way to add the LFS link association in the browser settings...

Thanks, it became clear for me now as well.

Quote from Nilex :

Normally it's installed with LFS

Yes but he has no normal install bcz cracker.