How many Checkbox are associated to Select Multiple?

[Ywy]

Hi all:

 

I start an application in PHP and SQL Server for a company car and I need some recommendations.

 

The application tracked him to the maintenance of the cars. On one side are the car brands (Ford, Chevrolet, etc.) with the relevant goods and associated services. A relationship many-to-many.

 

On the other hand, the executives (stage 1) enter the customer associated with their cars and the corresponding products and services. The customer goes to the mechanic who performs the action (step 2) and finally counter that the collection (step 3).

 

My main problem is how to link Client - Automobile - Services in the first form. Enter the name and telephone number after a multi-select will select the brand and asynchronously checkbox must be loaded in all services and check the corresponding to that mark.

 

 

I find it difficult to incorporate all the links on the form. Appreciate design recommendations database (customer table) and how to assemble the form. Maybe some of you made any similar application or know a reference.

 

Finally thank you in advance for the time can provide for review this post.