js get input from user

1var name = prompt("Please enter your name", "Harry Potter");

1var name = window.prompt("What is your name");
2document.write("Hello " + name);

1Copyvar name = window.prompt("Enter your name: ");
2alert("Your name is " + name);

1var answer = prompt("How are you? ");

1var person = prompt("Please enter your name", "Harry Potter");
2
3if (person != null) {
4  document.getElementById("demo").innerHTML =
5  "Hello " + person + "! How are you today?";
6}