Animation script with is.grounded help

Hi I have this animation script,

var .isgrounded : boolean = true;

function Update()

{

if(.isgrounded = true)

 {
    animation.CrossFade ("Walk");
 }

}

{

  if(.isgrounded = false)
 {
    animation.CrossFade ("Jump")
 }

}

I made it my self(That might be the problem). And what I'm trying to say is, if the player is on the ground play the Walk animation. But if the player in not touching the ground play the Jump animation. Now Unity won't even play my game now, it says there is a compiler error. This little script has been giving me a ton of trouble. Thanks for looking!

-Rov