Javascript input validation with while loop isnt working?

const choices = ["a", "b", "c", "d"];

let userChoice = prompt("Pick one from "a", "b", "c", "d": );

while (!choices.includes(userChoice));

alert("Invalid entry! Please re-enter!);

let userChoice = prompt("Pick one from "a", "b", "c", "d": );

alert("You picked " + userChoice);