I have a screen in which i have two dropdowns (dropdown_master and dropdown_model)
In dropdown_master i have a list of master-id's consisting of 4 numbers identifying the product family.
In dropdown_model i have a list of item-id's. The first 4 characters fo the item-id equals a master-id followed by x characters. So the first 4 characteres of the item-id specifies the overall product family while item-id's specify the specific product from within the productfamily.
What i want is to filter dropdown_model based on the product family choosen in dropdown_master. Right now i have the following code in dropdown_model: