Listpage calling details/listpage page

I have a Listpage1 (having custtable field custno, custname etc) calling another listpage 2.

Listpage2 two will show Custdetails table, and will bring up all the records having custno from the calling listpage 1.

For EP listpage2 will be replaced by the User control. All navigation works fine now apart from the fact that the details listpage and user control on the EP shows all the records at the moment.

How can I pass the custno and filter the details page using custno?