How can I get Illustrator to automatically resize the font to a designated page width?

I want to be able to type lines of text and have Illustrator automatically change the font size so that it fits that width of the page exactly, even if on one line there are 8 words and on another line there are 2 words - I want the big and small letters effect. I was previously doing this in Photoshop manually but someone suggested I could do it easier in Illustrator so here I am....

Thanks.

Jay