RadioButton\Dropdownlist\TextBox Validations

I need some help with coding validations.  I have a form that I have to first validate whether a Yes\No radio button was selected and if Yes is select a Panel will appear which contains 2 Dropdownlists and 2 Textboxes .   I need to valide those 4 fields in the panel to make sure that each one has been filled out and not left blank.    Below is sample of how it looks on the Form

 

Is Your Issue Concerning a Tape Release?   YES     NO  

(If they select Yes the following panel appears)

Tape Color: (this is dropdownlist)

Tape Number: (this is dropdownlist)

DateofVideo: (textbox)

Reason Tape is being Released:  (textbox) 
...