Searching 2 mysql tables for username and password

[rossco100]

hi,
i have created a site where the user logs in with an assigned username and password, on login they are asked to enter their prefared username and password to login with in the future.
I have 2 MySql tables piclogin (original table with preset details)
and newlogin which stores the new prefered username and passwords,

I used the coding below to do the original validation :

if($rec=mysql_fetch_array(mysql_query("SELECT * FROM piclogin WHERE username='$username' AND password = '$password'"))){
if(($rec['username']==$username)&&($rec['password']==$password)){


my question is: can a query be created to search both tables for the username and password entered? and depending on which table the information is found in, redirect the user to different web pages?

Thanks
Stephen