Automaticly go to next input text box

hey guys. well yeah i have a swf with 22 individual text boxes labled code1a_txt, code1b_txt and so on and each one has a maximum amount of characters set as 1 and what i was wanting them to do is when the user enters that one character i want it to goto the next text box automaticly without the user having to press the tab key. I know i have to make it detect that the maximum character has been reached and make it so the focus changes to the next text box i choose but i cant get it workin and ive searched the forums endlessly and found no info that can help. Hope one of u guys out there no how i can accomplish this cause its annoying and not as realistic as i want it to be when the user has to press tab for it to go to the next input text field Well thanks in advanced and hope someone can help.

come on guys.
cant someone help me out a little with this. you dont have to tell me the anwer if u dont want to but u could at least point me in the right direction like an examople code that does something similar to what im wanting to archive.

thanks hope someone out there knows how to do this if u dont understand what im on about im msn now as chevron8653@hotmail.com

even a little useful hint that will help.

Look into TextField.onChanged and static Selection.setFocus