I'm using Dreamweaver now to build a site. A lot of things are written by itself and some things really don't.
Now I'm trying to build a page where the user is adding a name and an e-mail.

I want my page to check that the e-mail isn't already in my table and that is pretty simple.
But, now I want this one to check if the e-mail is in either table_users OR table_members

So, if someone is filling in the form with their name, address and e-mail I want the query to check both tables if the e-mail isn't already in the system.
What would a query like that look like?

I thought this would work, but it doesn't.
PHP Code:
  $loginUsername $_POST['email'];
$LoginRS__query sprintf("SELECT * FROM table_users, table_members WHERE member_email=%s OR user_email=%s"GetSQLValueString($loginUsername"text"));