If/ else statements


Im making my game, and ive always had problems with if/else statements!
Please help me find out what is wrong, because it`s annoying that these codes always slows down my progress. Here is my code!

confirm ("Are you ready?");
var age = prompt("What`s your age?");

if(age is less than 13)
console.log("You are allowed to play, but i take no responsebility!");
console.log("You must help me!");


You cant use is less than! for less than use
age < 13
for more than use
age > 13.