Disabling the MAX_FILE_SIZE error.

I want to set the MAX_FILE_SIZE in my form for uploading files, but I don't want to have the error displayed on the action script when someone tries to upload a file that exceeds this limit. Because then I also get a warning from my session management like this: Warning: Cannot send session cache limiter - headers already sent by (output started .... I don't want to just make the MAX_FILE_SIZE really large and weed out the undesirables in the action scipt, because then precious bandwidth is wasted uploading a file for no reason. Is there something I can set in the action script to turn off the warnings. Thanks, Keith