I'm using IE8, I think. Is there any shortcut for subscript/superscript in a text field? [say, for a profile?]?

i'm taking an online algebra cl that lets you write notes in a little sidebar. it has bolding and underlining and other various capabilities, and they can be accessed through commands such as ctrl + B, or ctrl + I, etc. is there one for subscript and superscript? i have tried ctrl + shift + "+" and ctrl + - and ctrl + shift + -, but they don't seem to work. D: