I am trying to implement the following and I am just going to run it by you guys very quickly. I am not sure it's feasible but here's how it goes.

I 've divided our client list to certain types: private companies, governmental agencies, private individuals etc.

I am planning to have a data input layout whereby each one of them has a separate tab and the user just goes to the appropriate tab to fill in the details. So if it's a private individual they 'll click the third tab (in this example) and go on to fill their data. 

There's of course a field where the type of client will be inputted. 

How do I trigger filemaker so select from a list to fill in client type based upon which tab the user has selected?

Use on tabswitchtrigger to set a global variable. Then reference that global variable with an auto enter calc.

Thanks Brooks, much appreciated.