Forum Post: How to auto populate the fields values from one entity to another entity on selection of the custom button

Hi, I'm working on requirement like , I created one custom button ADD VALUES button in Custom entity Sales Order. In Sales Order I have 3 custom fields 1.Product Name, 2. Product Price and 3. Product Model. now When fill above fields and click on the custom button ADD VALUES I need to auto populate the above 3 fields values in Product Details Entity I do have same fields in Product Details entity. Can some one please help me how achieve this requirement. Thanks, Rahul