Pause online game

I am currently making an ORPG to play with friends and such and I am trying to implement a Menu where players can either log out, add friends, join parties, view stats, view inventory and those sort of things.

When that player presses a button (escape) it brings up a GUI with these options but the player is still able to move around (First Person Controller). I have tried disabling the scripts that control the players movement and mouse viewing (Character Motor + Mouse Look) but if the player is in the air and presses escape it locks them in that position.

What I am asking is how can I freeze the player so they can access the Menu without being able to move/look but also if they are mid air they continue falling.

If possible could you answer in Javascript..