How can i change the size of the font on the screen smaller by using CTRL key?

not the font that i type, but the font that u see when u go to any websiteHow can i change the size of the font on the screen smaller by using CTRL key?
ctrl and scroleon the mouse,it will unlarge and shrink it,you can also goto view and text and change it there.How can i change the size of the font on the screen smaller by using CTRL key?
if you have on your mouse a scroller button thingy, you hold down CTRL and scroll up or down - up to make it smaller and down to make it larger