PLZ help.when i click a joint it will switch between contract or extend and no relax or hold. this is a big problem so i hop you can help me soon!

Go to your settings. Mouse buttons is most likely set to 3; turn it back down to 1.

You can try the scrolling in the mouse, Maybe it will work

Try this:
1. Download lastest driver of your Mouse hardware.
2. Try changing mouse options, see if you have double-click activated.
3. See if you have any setting error (in toribash)

Have a nice day and good luck