how to make a field that is required to not to be necessary
I have a form with a radio button field that have two option , after that field i have two fileds with several option each on. What i want to do is : if the first option a the first field is selected then the first field after this field to appear and to be required, if the second option is selected then the next field to appear and to be required and the previous to dissapear and not to be required. If i put the both filed to be required from start, the form can not be completed because one of the two filed that is hidden is required and i message appear which warns me that a field must be completed , even if i do not want to be completed because the first option of the first field was selected, and the second field after the first it is hidden but required if the second option of the first field is selected .
How to make that possible ?