Hide/Show Fields

Hi
I am currently trialling PHP runner and think its great so far. Before purchase there is one thing I would like to be able to do but cannot seem to achieve. I wonder if anyone is able to help.
I am creating a database which logs procedures undertaken in our department. The master table is a list of clients. The child table is a log of the procedure. I wish to show only the relevant procedure fields based on a field.
For example:

If procedure = "injection"

then i need to show fields "site of injection, needle used, drug used, volume injected"
If procedure = "suture"

then i need to show fields "site of suture, suture guage, type of stitching"
for both procedures i would need to display "nurse name, nurse grade, date"
I would ideally like the relevant fields to displayed after picking the procedure from a drop down box.
Thanks