How can I switch from gm map to palyer map on the same pc?

I wanted to add a second monitor to my laptop for live table top games. How can I display the player map on the second monitor and have the gm map on my laptop screen?

If you're referring to having the GM and Objects/Tokens Layers open simultaneously, you could accomplish this by entering the game additional times through additional browser windows/tab. The same should work for viewing different Pages , as well.

As Silvyre rightly says, and helpfully links, the way this can be done from a single account is to have multiple browser windows open with the game loaded. On the 'player' facing screen you could head to the settings menu in game and select 'log in as player' to ensure a non-GM view is available. To have this work for all players you would need to make sure that your account is assigned as view AND edit all sheets that they would need access to (alternatively you could set both controls to 'All Players'). Because your private browser tab is still logged in as the GM you would still be able to influence the additional layers, access all sheets and handouts as well as move the players around the screen, between pages etc or even view other pages while your players deliberate whether that 'This is not a trap!' sign is actually a trap or not. If you have concerns about accidentally displaying sensitive game information to the players an alternative course of action would be to have a second 'Player' account which you would invite to the game and log in as on the public monitor. Again, this account would need to have access to view and edit any sheets they might want up on the screen during play or as before 'All Players' would give the desired result also.