Constant questions

Hi, I have two questions involving Constants. 1. I want to refer to a refer to a Constant by its value (which is unique), and return its name. E.g.,: define ("SEND_DS","1"); define ("SEND_DS_ACK","2"); define ("RESEND_DS","3"); define ("STARTUP_DS","12"); For example, if I receive "3", I would like to echo "RESEND_DS"--the name of the constant. Is there a simply way to do this? Or am I better using an Associative Array (which is what I was thinking)? Then I could such refer to an element by its key or value (both of which are unique). I suppose this more of a performance/elegance issue, than outright problem. Just curious what you think. 2. Let's say I have a Constant called MY_NAME, the value of which is "Rene", and I pass it to a function, such as: function example ($val) { echo ???????; } example (MY_NAME); Such that the output will be MY_NAME. If I echo $val, the output will be Rene. But I want to see the constants Name, not Value. Any ideas? Thanks. ...Rene