How to compress MySQL ids without leaving spaces

Question

Possible duplicate:
Make MySQL auto-increment id (re) start at 1

I have a huge 100,000 rows in a MySQL table. How to compress lines of automatic increase?

At the moment it looks like

id | col1 | col2 ------------------ 1 | foo | bar 2 | foo | foo 4 | bar | foo 12 | bar | bar 

I would like the identifiers to be 1,2,3,4:

 id | col1 | col2 ------------------ 1 | foo | bar 2 | foo | foo 4 | bar | foo 3 | bar | bar