Parameters passing doubt in Jasper reports

[Thirugnanam Saravanan]

Hi All,

I am very new to Jasper Reports and iReports. In my application there is a query similar to the below in the jrxml file:

 select  d.user_id ,e.cust_name,pref_group_desc, pref_desc, c.pref_group_type from ipass.user_prefs a, 
ipass.preferences b, ipass.preferences_groups c, ipass.users d, ipass.customers e 
where d.user_id=a.user_id and a.pref_name = b.pref_name and b.pref_group_id = c.pref_group_id 
and d.cust_id=e.cust_id and d.user_type in ('U', 'G') $P!{USER_ID_Q} $P!{CUSTOMER_Q} $P!{PREF_DESC_Q} $P!{PREF_GROUP_DESC_Q} order by cust_name,user_id, pref_group_type, pref_desc $P!{FETCH}

I can understand that USER_ID_Q,CUSTOMER_Q,PREF_DESC_Q, PREF_GROUP_DESC_Q and FETCH are parameters. But I dont understand how to pass values to this query in runtime when i preview this report in iReport. When I gave some random values for this parameters during preview. I am really confused with the ! (exclamation mark) in the parameter syntax. can some one explain this with a simple example?