Possible Duplicate:
When should “into” be used rather than “in to,” and vice versa?
I was recently submitting ("checking in") some data to a database and composed an email to my team informing them of the submission. What's the proper grammar to use here:
The changes are checked into the database
or
The changes are checked in to the database
What's the rule of thumb for proper usage between the two? Is there even a difference?