Ok smeone tell me where I'm wrong here [duplicate]

` ` ` 
var fn = document.forms["myForm"]["first-name"].value;
var pw = document.forms["myForm"]["password"].value;
}
if(fn=="giannis" && pw=="1234");
{window.location.href="index.html";
}
else {
alert("Invalid username or password")
}
` ` ` 

Well I have error in the word else and I can't see why. I asked a friend who is good at js and he told me to come here