Design Pattern: How to make a MessageBox

As the title say, I want to make something similar to a MessageBox or Alert box.

I'm already quite familiar with basic Unity stuffs and know how to make a MessageBox with Unity UI 4.6 or NGUI, so I'm not asking about how to use an Image as background or Text as message.

What I'm asking is that how can I make something like a static function or whatever that let me create the UI using 1 line of code like:

 MessageBox msgBox = new MessageBox("Title", "Message");

or

 Alert ("Well done");

from anywhere in the program. Thanks.