(YET ANOTHER) Parse Error!

I know I keep posting parse error complaints, but I'm a beginner with php.

Error:
Parse error: syntax error, unexpected '}' in /home/content/14/7688814/html/812/register.php on line 28

This is about were the problem was. The } else { is line 28.

 if (isset($_POST['username'])) {

$un = 'escape_data ($_POST[username])' 

 } else {

 echo '<p align="center"><font color="red"><b>Please enter a username!</b></font color></p>';

 }

Code (markup):

Thanks for helping in earlier threads!

 

Change:

$un = 'escape_data ($_POST[username])' 

Code (markup):

to

$un = escape_data ($_POST[username]); 

Code (markup):

 

This is the second time you've helped today! Thanks for everything!