Click the red error message, if there is any found, and select the correct spelling.
Notice that the spelling turns from red to green once it has been corrected.
You've probably noticed a few people checking lots of random pages really fast for incorrect spelling, I bet you want to know how to do that. These steps will tell you how to speed check all spelling on forms really fast.
Click here and download Google Toolbar.
Click ABC Check and you will notice all the forms on your page turn blue, the spelling errors are in red.