Error on line 30

[Fragma]

I keep getting this error:

"Parse error: syntax error, unexpected T_VARIABLE, expecting ',' or ';' in /register.php on line 30"

The code on lines 29, 30 & 31 is this:

PHP Code:

$query = "INSERT INTO tablename (username, password, email, ip) 
        VALUES ('$username', '$password', '$email', '$ip')";
        mysql_query($query); 


Can anybody spot where the error is? It's been driving me mad all day.