[Andreas]

I assume the table name (vb3_user) is correct?

PHP Code:

$query = "SELECT * from vb3_user where 1 and username like '$username'"; 


You should better change this to

PHP Code:

$query = "SELECT * FROM vb3_user WHERE username = '$username'"; 


Also replace

PHP Code:

$result = mysql_query($query); 


with

PHP Code:

$result = mysql_query($query) or die('Query not successful: ' . mysql_error()); 


to see what's going wrong with the query.