update several records at the same time

I have a form with dynamic table (PHP/MYSQL) where some records are been show with checbox and i want to update this records with one button click by selecting or deselecting the checkboxes. My checkbox checked value is set to 2, blank will be 1 (default on mysql table).

Any sugestion or example for this updates?

My table

ID | CHKBOX1 | CHKBOX2 | CHKBOX3 | CHKBOX4
1  |   x     |    X    |         |    X
2  |   x     |         |    X    |    X
3  |         |    X    |         |    X
4  |   x     |         |         |    X