pop up confirmed + alert in javascript

Question

how do I make confirmed pop up by alert for user's data in form, for example :confirmed box: dear (user name) are you sure? alert box: thanks for submission (user name)

Answer 1

There are the functions confirm and alert :

username = document.getElementById("Username").value;
confirm("dear " + username + " are you sure?"); 
alert("thanks for submission, " + username);