Untitled

<!DOCTYPE html>
<html>
<body>
<form>
<br>Hidden<br>
<input type="text" name:"username">
<output name="c" form="username>
</form>
</body>
</html>

When you type you're username into the input box I want a information to appear in the output box like:
[URL=http://www.example.com/example/users/information from input box here[IMG]Image URL I want[/img][/url]