How do I change youtube's video size?

Well I was on youtube and the size of the videos and other stuff drastically changed and I just want the basic size not the big one. How do I change it back?How do I change youtube's video size?its one of the little boxes in the bottom right hand corner of the video box thingHow do I change youtube's video size?just click on the buttons on right hand side bottom of video%26gt;%26gt;%26gt;How do I change youtube's video size?its a box that has arrows pointing inward.How do I change youtube's video size?press the %26quot;Esc%26quot; key to get out from the large videoHow do I change youtube's video size?theres a little thing on the bottom right corner of the screen,just put your mouse over one of them and it will say %26quot;Full Screen%26quot;.