*trick to remove chatbox in gmail:

How to Completely Remove Chat Box in Gmail:

• Login to your Gmail Account
• Click on the Star (Setting) button and select the Settings option from the drop down window.

• Now click on the Chat tab.
• In the Chat tab look for the Chat section, in this section select Chat off option.

• Now click on Save Changes button.

That’s it! Now no one can interrupt you while you are on Gmail. You can also make yourself online whenever you want to. Just click on Chat On button in fourth step