impossible syntax error - query does not like AND operator

[DLR]

Please see if you can see the mistake I must be making. I keep getting the error

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '@signforce.co.za AND client_dbase = signforce AND worker_status = 1' at line 2

 

$a = $_SESSION['worker_name'];
$b = $_SESSION['worker_email'];
$c = $_SESSION['client_database'];

$query = "SELECT * FROM staff 
WHERE worker_name = $a AND worker_email = $b AND client_dbase = $c AND worker_status = 1 ";

$result = mysql_query($query) or die(mysql_error());

This should be sooooooo simple!

 

Thanks

[PFMaBiSmAd]

String data in a query must be enclosed in single-quotes so that it is treated as string data instead of keywords or identifiers.

[DLR]

Thank you. Solved, but  I have tried that over and over - still same error, yet now . . . oh well.