@Skript-Kiddy
Why not use keyboard-shortcuts for closing a document?
For example, i defined
[CTRL] + [^]  to close a document
[CTRL] + [SHIFT] + [^]  to close all open document at once
And [CTRL] + [TAB] is predefined for switching through the open documents.
Try this, and you won't need a button at the tabs 
