Código para pedra, papel e jogo de tesoura

var userChoice = prompt("Do you choose rock, paper or scissors?");

var computerChoice = Math.random();

if (computerChoice < 0.34) {

computerChoice = "rock";

}
else if(computerChoice <= 0.67) {

computerChoice = "paper";
} 

else {

computerChoice = "scissors";
} 
console.log("Computer: " + computerChoice);

var compare = function(choice1, choice2) {

if (choice1 === choice2) {

    return "The result is a tie!";

}
else if(choice1 ==="rock"){
    if(choice2 ===scissors)
    return "rock wins";
}  
else if(choice1 === "paper"){
if(choice2 === rock)
        return "paper wins";
}
else if( choice1 ==="scissors") {
    if(choice2 ==="paper")
        return "scissors wins";
}
};