Where did my 'Back Button' go?

I have a Google toolbar on my IE browser. I also have a Yahoo toolbar. My problem is that oftentimes, I lose my back buttons. I cannot go to the previous page, because I have no button to click on. These aren’t new windows, they are the same one, and the back buttons aren’t grayed out-they are not on my toolbar!
Can you help me?

Thanks,
hh

ALT+left arrow key.

Or Backspace.

I think that in some set ups [, {, and ( work as well. And the corresponding closing ], }, and ) move you forward through your history.

I use Mozilla Firefox and 3 ways to go back work. They are ALT+left arrow key, right click mouse then click on word back and the Back button.

I never heard of a back button. The one on your front is the belly button.