Selecting previous and next rows based on the current row is a common task in most web applications, Take this blog when viewing a post, their are the previous and next posts available at the bottom of each post.
MySQL makes this a simple process the following will get the previous row that has an id less then 2:
Using a sub query in the where clause you can use min and max to return the previous or next row:
//Previous row
SELECT id FROM table WHERE id = (select min(id) from table where id > '2'
​
//next row
SELECT id FROM table WHERE id = (select max(id) from table where id < '2'