Scripting Error Help Needed

I’m a newbie and making a game where you are a ball and you roll around and stuff but when I scripted the jumping it stopped working and gave the errors, expecting ), found ‘=’.
Also ‘;’ expected. Insert a semicolon at the end. But I’m not aware of where I have missed a semi colon. Could anyone help me please?
Here’s the code it is not very long

var rotationspeed = 100;
var jumpheight = 8;

private var isFalling = false;

function Update () 
{
	//Handle ball rotation.
	var rotation : float = Input.GetAxis ("Horizontal") * rotationspeed;
	rotation *= Time.deltaTime;
	rigidbody.AddRelativeTorque (Vector3.back * rotation);

	if (Input.GetKeyDown(KeyCode.W) && isFalling == false);
	(
		rigidbody.velocity.y = jumpheight;
	)
	isFalling = true;
}

function OnCollisionStay ()
{
	isFalling = false;
}

Your problem is that you’re using parentheses on line 14 instead of brackets

your if statement should look like this

if (Input.GetKeyDown(KeyCode.W) && isFalling == false)
{
   rigidbody.velocity.y = jumpheight;
}

You don’t need the semicolon after the if statement on line 12:

if (Input.GetKeyDown(KeyCode.W) && isFalling == false)