You might want to learn scripting a little bit so you can help yourself later and save time, since most people here ignore such a small, easy request like this (well, at least they think so).
You only need to add/replace two lines of the default script to obtain your need. Here's how:
1. Find
Game_Actor.
2. Find
def exp=(exp).
3. Add this line at the last line of the method (before the
end):
# Heal HP and SP
@hp = self.maxhp
@sp = self.maxsp
If you also want to heal character during an event level-up, do it also at
def level=(level) method.
That should do it.