Enemy AI Help?

I keep getting a error when I try to use this enemy AI scrip. Here is the error “Parsing error” and here is the script-

{
    	var distance;
        var target : Transform;    
        var lookAtDistance = 15.0;
        var attackRange = 10.0;
        var moveSpeed = 5.0;
        var damping = 6.0;
        private var isItAttacking = false;
     
        function Update () 
        {
        distance = Vector3.Distance(target.position, transform.position);
     
        if(distance < lookAtDistance)
        {
        isItAttacking = false;
        renderer.material.color = Color.yellow;
        lookAt ();
        }   
        if(distance > lookAtDistance)
        {
        renderer.material.color = Color.green; 
        }
        if(distance < attackRange)
        {
        attack ();
        }
        if(isItAttacking)
        {
        renderer.material.color = Color.red;
        }
    }
     
     
    function lookAt ()
    {
    var rotation = Quaternion.LookRotation(target.position - transform.position);
    transform.rotation = Quaternion.Slerp(transform.rotation, rotation, Time.deltaTime * damping);
    }
     
    function attack ()
    {
        isItAttacking = true;
        renderer.material.color = Color.red;
     
        transform.Translate(Vector3.forward * moveSpeed *Time.deltaTime);
    }

Remove the ‘{’ on line 1. Line 2 should be:

 var distance : float;