使用javascript中的变量设置填充表单字段

I have a form in my play framework project. The user inputs a series of values. I need to store another value in my model as well but I don't want it to be displayed, it has to be hidden. The other complication is that I want this hidden value to store the value of a variable that is determined after the form has been submitted (because it uses one of the values entered by the user to get the variable). Is there a way to do this or would I have to create a separate model to handle this?I have a form in my play framework project. The