Hi, I'm trying to do a simple case of displaying a submitted value but I'm getting a blank output.

This is my form:

<form action="name.php" method ="post">

<input type ="text" size ="45" name="username">
<input type ="submit" value="submit">


This is the output page:

echo("your name is $username");

and the output is just:

your name is

What am I doing wrong?