Celaring values in display file fields

I have created an RPGLE program that 

1. displays a simple display file where the user enters in a social

2. The program then takes that social and then checks to see if the number 
exists in a physical file

3. If so it then displays a second display file with the data from the file, 
and if not it display the same second display file with blank values for the 
user to complete.

On this second display file I have enabled the F12 function key to allow the 
user to move back to the first display file to re-enter a new social, but for 
some reason when you do this, it displays the SECOND display file with the same 
data it did the first time?

How do I clear those fields so this doesn't happen?