Client script

[Ram012]

Create One list type field reference to User table . When someone removes any values from the list or add any users to the list fields , then it will shows the alert/ pop - up with the added/removed users list to the end user.
Using incident table(OnChange).

Any idea how to build the above scenaior help me.

[Mark Manders]

Why do you want to show someone a message of something they just did? I delete James from the list and the system tells me 'hey! you deleted James'. 

It can be done, but it's a list, so what are you expecting? Because when I remove one and then another one, I will get two messages. If you add/remove in bulk, it will need to show all. Because there are many ways to add/remove users, you could be creating multiple messages, not really making is a good user experience (and I am still hanging on why you would tell somebody something they already know).

For this to work you need a client script (onChange of your field) to show the message and to get the users you will need to have a script include and Ajax call to get the user's name(s), since list fields are stored with sys_id's. You need to send the previous and new value of the field and show the differences.

[Sandeep Rajput]

@Ram012 This can be implemented easily, however what is the use case here?