ask about make vbulttin plugin

i started to make plugin for vbulltin but i want to ask some question

the plugin target is to allow users to deny other users from watching o开发者_如何转开发wn profiles

my questions is

when user try to watch my profile but i deny him to watch my profile

1 - how can i show error message like

this vbulltin error

https://www.vbulletin.com/forum/showthread.php/4555112245-Style-Manager-loading?p=4555112245#post637634

2 - how can i add option in user cp

3 - can i add new specific file to vbulltin and get info using ajax

mean : when user add userid and click ignore

i send request to new page called "ignorethisuser.php" and this page contain my php code ???