variable tracking overview

Could someone give/sell me a clue as to variable tracking and/or cookie usage over multiple form pages for multiple users? Environment: website Number of variables: 390 or so. I have 4 pages of forms, 4 result pages, and want to email all the results. I put up one page of forms, they input, it spits the output to the result page. Each input/output works fine until the final output which comes up totally empty. This session tracking code (hopefully) heads the input pages <? if (!isset($id)) { srand((double)microtime()*1000000); $randval = rand(); setcookie("id",$randval,time()+14400,"/",".mywebpage.com",0); } ?> It is shown as echo "Your session number is $id"; which shows up on every page except the first. If I link the email output page to the first input page form, it outputs the INFO SENT html page and the email with all of the page info, so that part is working. It just doesn't track across several forms and if two people are logged in concurrently, the same session id number is used for both users. Arrrrrrrrrrrgh! What am I missing here? Should I be creating a database for this one-time-use info? (Of course, the client dragged his feet for 5 months and now needs to get it rolling yesterday. I would appreciate any help ASAP.) Thanks. Larry