Forms data clash between players

Okay, so i use blocksniper's api by @Sandertv to send forms, so i am trying to make a server shop plugin, so i store id and metedata of the item player chose in Window.php, but when many players access the shop forms, the data clashes between window, the id changes to the last person who accessed the form, how do i fix this?

 

Store it in an array where playerID is the index

 

and when do i unset the array? how do i know that the player closed the window?

 

well, I don't think you're storing large amount of data in there so I suggest leaving the data in the array (also a nice selection save) until the player disconnects.

 

awesome thanks!