I'm trying to create a webform that includes product line items, but haven't been able to figure out how.  Any suggestions?

I'm trying to create a really basic trigger.  Essentially what I'm looking for is that when a specific line item is added to an opportunity, a field in the related account record is updated.  Here's an example:

 

Company ABC has always purchased purple widgets, so they're on our 'purple widget' campaign - as defined by the (custom) Marketing Campaign field on the Account Record.  Today, they purchased blue widgets. So we want to change the Marketing Campaign field from purple widget to blue widget.

 

I'm thinking that this should be a fairly easy trigger.  Could anyone point me in the right direction?

We're just in the process of migrating to Salesforce.  Our existing CRM has the functionality to automatically FTP order details to our warehouse.  The specific details that are transmitted include:

• invoice number
• ship to address information
• line item information (i.e. product name, product id # and quantity)

I've searched through the Ap Exchange and don't really see anything there that meets our needs.  Has anyone done something similar? Or does anyone have any suggestions about where I can start to look?

Thanks!

I'm trying to create a webform that includes product line items, but haven't been able to figure out how.  Any suggestions?