First time working in Unity i need help.

So im first time working in unity and im following war nations tutorial.
On the tutorial they have a different version of unity.
I get expecting EOF found }.I tried many combinations when i fix one error another one comes!
This is my Script im adding guns to my game:

#pragma strict

var Bullet :GameObject;
var Ammo : int = 30;
var FirePoint :GameObject;
var FireMode : String = “Semi” ;

function Start () {
}

function Update ()
{
if(FireMode == “Semi”)
{

if(Input.GetMouseButton(0))
{
FireOneBullet ()
}

 }  

}
}

function FireOneBullet(){

{
instantiate(Bullet ,FirePoint.transform.Position ,transform.rotation);
Ammo–;
}

too many parenthesis.
perhaps rewrite it.