Ajax dropdown menu from MySQL database

[Spira]

Hi

I am pretty new to Ajax, and want to do the following or know if it is possible:

I have an Employee database (MySQL). In the Financial Department there are several Sub-Departments(i.e Debtors, Creditors, Salaries, etc)

With the finance department the following is needed:
There should be a drop down menu as follows:
"Which division are you looking for?" (Then in the dropdown menu it should have all the sub-departments for the finance department)

This is where the tricky bit comes in:

1)Only when the DEBTORS sub-department is selected, should another drop menu appear, which lets them select a store code. (Menu heading: What is your store code?)
Once the store code is selected, the store name should be displayed.
Below this, the format of the employees should be displayed for that particular store as follows:
Heading: Query Handling - Under this would be the employee with all details(name, job responsibility, tel, fax, email)
Heading: Query Escalation - The manager/s will be listed under this with all details

2)If either Guild, Customer Care, Salaries or New Business sub department is selected, there should be no "What is your store code?" dropdown menu. In these cases, all employees should be listed in the style of the rest of the website ie. Manager at the top, and employees at the bottom.

3) If either Warehouse, Build It or Dropshipment sub department is selected, there should be a dropdown menu "What is your store/supplier name", which lets them select the store name.
Once the store name is selected, the store name should be displayed.
Below this, the format of the employees should be displayed for that particular store as follows:
Heading: Query Handling - Under this would be the employee with all details(name, job responsibility, tel, fax, email)
Heading: Query Escalation - The manager/s will be listed under this with all details

Is this possible, and how could I achieve this?