Hi:<BR><BR>This is my first time posting, so I'll try to keep it brief. I'm building sign-up page that will create a new database record for each new user. Of course, I want to ensure each user has a unique record. I could execute SQL that searches through the user DB looking to see if the new user's email address or user ID is already present in the DB. <BR><BR>This could put a drag on performance if the user DB held thousands, or even tens of thousands of existing records (greate problem to have!). Is there a better, more efficient way to go about this? I'll take *any* help I can get, but links to articles or tutorials would probably be most useful. <BR><BR>I'm developing with Access, but will use the Microsoft upgrade tool to upgrade to SQL Server. Any assistance would be most appreciated.<BR><BR>Thanks!