enemy is destroyed at the start instead of when health is 0

heres my script

var health = 2;

function Update() {
if (health <= 0);
Invoke ("Die",0);
}

function ApplyDamage () {
health -= 1;
}

function Die() {
Destroy (gameObject);
}

the enemy is destroyed at the start instead of when it has 0 health, also i have another script which sends ApplyDamage when the enemy gets hit

Try getting rid of the semi colon after the if statement. if (health <= 0);