<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title> JavaScript Prompt Dialog Box </title> </head> <body> <script> var name = prompt("What's your name?"); if(name.length > 0 && name != "null") { document.write("Hi, " + name); } else { document.write("Hello Anonymous!"); } </script> </body> </html>
