We are using this function to check if all the text fields are empty or not.
argument is "value 1", the control's id attribute will be my_radio_value_1.
This is the name to be used when referring to the control's value in the POST/GET superglobals, after the form is submitted.
This is also the name of the variable to be used in custom template files, in order to display the control.
I have a form with 3 radio buttons for my register form - users could choose one of 3 user roles.
If you choose first radio button, you see following dropdowns: region, school, teacher, class and class divisions, for radio button 2 - you see the first dropdowns but without teacher.