Help with TextBox

I am making a chatting gui kind of thing, and I was wondering if there is any possible way to view highlighted text in a TextBox. Like for making a certain bit of text bold with the click of a button.

Thank you,

Of course if it is possible to highlight text in some way with textbox and even any GUI element, for that you can visit the following information about RichText This property allows fonts like bold, italic, placing colors in a text, etc.