How to use <script> tag to create a pop up for a website ??

Question

I want to know how can we use <script> tag in html to create a pop up which ask the name and email id of a visitor who opens the website.... Pls tell me...

Answer 1

<script>
var name = prompt("What's your name");
var email_id = prompt("What's your e-mail id: ");

alert("Your name is "+name+". And your email id is "+email_id);
</script>

Answer 2

And where can we use this code in our html code pls tell me that also.. ?? And where the data will get stored ??or not ??am confused...