php form help

[sethupathy]

here is my problem,

 

I need your ideas guys on how to implement my form,

 

Situation : I have to create a web form that has to be filled out by clients who have a main installation + 2 to there sub installation.

in total i have over 150 instalation some with only one main istalation and some with sub intstalaltion.

I need to create an entrypage to the form that will identify the number of installation.

 

I guess the best way to (ID) identify them individually would be the postal code.

maybe validate the postal code? but i do not have a list of all there postal code. should i let them enter the number of instalaltion and then make them submit there postalcode to the database. how to i relate the entry to the form?

 

PLS HELP i will be home all day working on this

 

Thanks a bunch