Client side javascript for multiple drop downs

I need a function for a mobile phone look up service. Contains two drop down boxes. Box 1. - Mobile Handset list Box 2. - Network list Certain models are available on certain networks. I need to have a client side java script that if you select a handset it will change the values in the network box to a list that the handset is available on. And vice versa, if you pick a network then the list of handsets will change to handsets that are available on that network. The lists need to be populated by a .js file that contains the list of handsets and networks probably in arrays. These arrays will need to be updateable to allow for more handsets and networks to be added/removed as required. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Installation package that will install the software (in ready-to-run condition) on the platform(s) specified in this bid request. 3) Exclusive and complete copyrights to all work purchased. (No GPL, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site). ## Platform Needs to work in ie 5 and above and mozzilla 1.1