To redirect https to http

The real situation is like this. I have 1 info page named as http://www.test.com. Inside this info page has a link to my secure site https://www.testonline.com (with secure cert). My problem is if somebody key in manually the https://www.test.com instead of http://www.test.com, The page will show certificate error and cannot redirect to http.

My target is to if somebody key in the https://www.test.com it can be redirect to http://www.test.com page and without certificate error message

Can somebody advise me the solution. Thank you in advance.