variable from another field in Fetch feature.

variable from another field in Fetch feature.

    Hello, lets said I have an app with 3 Forms: Local, National, Int. each form has the same information of products (Name, Code, and Price) except for the price, this is the different field on every Form.

   I have another form to sales, there I will select which pricelist would use, so I have a field named "Source" and it will be filled with the name of the Form I want to use, then I'd like to write an script to get the price of the appropriated list, something like:

input.Price = Source [ID == Name].Price;

   the thing is that I don't know how would be the correct syntax of the script to recognize that Source will be the value of the input.Source field.

      Can somebody help me?

Thanks in advance!

Mauricio