Alternative to Javascript prompt box for younger users [closed]

Can anyone can suggest an alternative to Javascript prompt box that is better for young users?

prompt("Please enter your name:", "Harry Potter");

Check it out.

Since the input box needs to be designed for children, I want the prompt box to be more colorful and lively. Any suggested existing box that I can use?
The requirement is that I have to let the user enter a string, receiving it.

Answer

Have you tried the jQuery UI library?

Here you can see an example of a modal form

You can modify the styles or select from different themes.