Why won't my player rotation script work?

I have been having trouble with my code it has four errors that I don't know how to solve:

         if(Input.GetAxis ("Mouse X") < 0)
         {
             transform.Rotate (Vector3.up) * speed;
         }
 
         if(Input.GetAxis ("Mouse X") > 0)
         {
             transform.Rotate(Vector3.up) * -speed;
         }
     }
         
 }