Instantiate a projectile on key press "F" key / OnMouseDown! Help!!!

Okay so again I’m stuck, I want a prefab of a sphere that emits which I have created to get fired/(instantiated) out from the player_character I have when either I click the “left mouse button” or hit the “F” key. The Sphere is tagged as “PlayerProjectile”. I’m assuming it’d be something on the function Update like
function Update()
if(Input.GetAxis(“Fire1”) >.1)
instantiate.“player projectile”;
I know that’s the wrong way it’d be written I just need a little help. Thanks!!! Also if anyone could throw it I have an enemy cube with a health GUI display and a health variable and i need a way in that enemy’s health script to detect if its been hit by one of these PlayerProjectiles and lose health accordingly. The Script on the Enemy Cube is -
var hp:float;
var maxhp:float;
var healthbarWidth:int;
var myHealthbar:GameObject;
var myhb:GameObject;

function Start(){

function Update(){

myhb.transform.position=Camera.main.WorldToViewportPoint (transform.position);
var healthpercent:float=hp/maxhp;

Of course that part won’t do me any good until i can actually fire the projectiles. Thanks for any help in advance. : )

if(Input.GetKeyDown(KeyCode.F) || Input.GetKeyDown(KeyCode.Mouse0))
Instantiate(Prefab, transform.position, Quaternion.identity);

Format your code correctly next time, please. It is hard to read as it is now.

Sorry it messed up when I posted it. it was indented and everything in the text box when i typed it in! : s