Adding script during runtime

So basically what I am trying to accomplish here is a script that adds a specific behavior script to the gameobject when I click. I have another script called behavior that does all of the general stuff an object should do, and different scripts that inherit from behavior. I want to add one of the different scripts to the gameobject when I click.

Unity gives me the error that Placer.PScript is a field but a type was expected.

Placer is the name of this script btw.

public Behavior PScript;
void Update () {

PScript is the name of a variable, you need to pass the type, also try avoid overriding unity component names