What does the PHP error message “Notice: Use of undefined constant” mean?

Question

PHP is writing this error in the logs: \"Notice: Use of undefined constant\".

Error in logs:

PHP Notice:  Use of undefined constant          


        

Answer 1

Am not sure if there is any difference am using code igniter and i use "" for the names and it works great.

$department = mysql_real_escape_string($_POST["department"]);
$name = mysql_real_escape_string($_POST["name"]);
$email = mysql_real_escape_string($_POST["email"]);
$message = mysql_real_escape_string($_POST["message"]);

regards,

Jorge.