newbee question

[<ross]

Using mysql with php I have a database that has a unique value for the user id. when
people get delete off the list I want the unique numbers to compact down so.

user id 1
user id 4
user id 5
user id 7
user id 9
user id 10

becomes 

user id 1
user id 2
user id 3
user id 4
user id 5
user id 6

If this is not possible how can I find the first entry in the database and last entry with
php/mysql?

R.