Rock,Paper or Scissors. Game

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";
}
var compare = function(choice1,choice2){
if (choice1 === choice2){
return "The result is a tie!";
}
if (choice1 === "rock"){
if (choice2 === "scissors"){
return "rock wins";
} else {
return "paper wins";
}
}
if (choice1 === "paper"){
if (choice2 === "rock"){
return "paper wins";
} else {
return "scissors wins";
}
}
if (choice1 === "scissors"){
if (choice2 === "paper"){
return "scissors wins";
} else {
return "rock wins";
}
}
};
compare (userChoice,computerChoice);