BCE0043 and BCE0044 errors, expecting ), found '.' and unexpected token )

I'm a bit new at using Animations, and I've had a hard time getting them to work. I've made separate scripts for each movement and action. Here's a basic Jump script that for some reason, isn't working.

 #pragma strict
 
 function Start () {
 
 }
 function Update () {
         if (Input.GetButtonDown.("Jump"))
     animation.CrossFade ("Jumping");
 }

Here are the errors.

Assets/Jumpscript.js(7,40): BCE0044: expecting ), found '.'. Assets/Jumpscript.js(7,49): BCE0043: Unexpected Token: ).

I'm running Unity 5.3.4f1 by the way.