Open New Field

Hi

I think it easy

I New in PHP, but i study

i have table
Car#

Date:

DriverFullName:

CustomerPayment:

p1

p2

p3

p4......

Total
i want that dispather

when he put payments just see only one field

when he put payment in (p1)open Field (p2)and t.d

so i want table look:
Car#

Date:

DriverFullName:

CustomerPayment:

p1
Total

Thank you