Why my ?ibwa=,Sessions not working ?

[kalmen]

Hi,
I am recently trying to learn PHP421, and
IBWebAdmin, my problems is

1. why it seems that the 1st time I
   installed and run login script...
   http://192.168.0.159/ibWebadmin/database.php?ibwa=somthing_23cjvjv3453454 ,the session
   can be auto appear ? But right now when
   I try it again ,it seems that the
   "?ibwa=somthing_23cjvjv3453454" cannot
   appear and the web page show blank .
2. Is this "?ibwa=somthing_23cjvjv3453454"
   the sessions or cookies ?
3. where can I find it in windows and how do
   I clear it ? my questions is why it show
   at the url of my ie browser , when
   mannually type
   "http://Webserver/ibWebadmin/database.php?" ,
   it drop down the comboBox and let me
   select ,where win98 store those infor ?
   Temp directory ? but I search I cannot
   find it.
4. is there any documents about those things
   ""?ibwa=somthing_23cjvjv3453454" which I
   can learn from ?
5. I try phpinfor() in a demo.php it work
   fine! Env=php421,Xitami Server , Win98Se.