I am not a real tech person so I really could use some help in reference to databases.

I have two different web sites. One is php and the other is asp.net. Not real smart I know have two different formats. Did not know any better at the time.

So my question is I want to be able to have the databases talk to each other so the members will only have to log in once and have only one membership.

One database is mssql and the other is mysql is this possible? If so please explain so I can see about doing or hiring someone.