When you open compose section in Gmail, how do you add the button for "justify"?in the tool bar.?

In the Tool Bar Right Align, Left Align,Center Align are available but not the button for 'justify'
When you open compose section in Gmail, how do you add the button for "justify"?in the tool bar.?
Goto mail help
Reply:Dont know...... when u get the answer, do let me know also.


Thanks.
name naming