How to Add Custom Contact Form

I’m trying to create a custom contact form popup that prompts the user for their email and password with a submit button. I also don’t want the HTML used in the popup to show on the page after the user submits their contact details. I’ve honestly been trying to make this work for a while but I’m still stuck at this simple example.

<script type=’text/javascript’>
var person = prompt(“Please enter your name”, “Harry Potter”);

if (person == null || person == “”) {
txt = “User cancelled the prompt.”;
} else {
txt = “Hello ” + person + “! How are you today?”;
}
</script>

Any help would be appreciated.