EnemyAI Script help

Hey guys I have a EnemyAI Script, but I always the error "Operator < Cannot be used with a left hand side of type "object" and a right hand side of type "float".

Once

And

"Operator < Cannot be used with a left hand side of type "object" and a right hand side of type "float".

Three times

Here is the script, Thanks For Your Help!

 var Distance;
 var Target : Transform;
 var lookAtDistance = 25.0;
 var attackRange = 15.0;
 var moveSpeed = 5.0;
 var Damping = 6.0;
 
 function Update ()
 {
     Distance = Vector3.Distance(Target.position, transform.position);
     
     if (Distance < lookAtDistance)
     {
         renderer.material.color = Color.yellow;
         lookAt();
     }
     
     if (Distance > lookAtDistance)
     {
         renderer.material.color = Color.green;
     }
     
     if (Distance < attackRange)
     {
         renderer.material.color = Color.red;
         attack ();
     }
 }
 
 function lookAt ()
 {
     var rotation = Quaternion.LookRotation(Target.position - transform.position);
     transform.rotation = Quaternion.Slerp(transform.rotation, rotation, Time.deltaTime * Damping);
 }
 
 function attack ()
 {
     transform.Translate(Vector3.forward * moveSpeed * Time.deltaTime);
 }