Doing so is a bad idea. The least you must do is check the names of the parameters you have been passed. Otherwise, everyone will be able to change the values of variables within your script at will; even those you did not intend for public consumption. Say you have a $filename in your script and someone passes filename=/etc/passwd to your script.. depending on your script's innards, a lot of malady might happen. CGI scripts are a very hostile environment and you should never trust any of your input data. I urge you to read Ovid's excellent CGI course to learn a sense for the potential problems.

Makeshifts last the longest.