Web Forms :: DataList Pagination - Show Product Related To Selected Item From DropDownList

I have

1-datalist (that use pagination)  
2-dropdownlist  
3-button=Ibtnselect1 in my page 

and these are my table in database

HOuse_info table

Id Behcode Region name

1 1115 1 Store1
2 1116 2 Store2
3 1117 2 Store3
4 1118 5 Store4

House_p table

Id Behcode Name Description Model

1 1115 Iron Test Q2
2 1115 Vacumcleaner Test2 Cv21
3 1117 Carpet Test3 Xs23
4 1116 Furniture Test4 Df23

Region table

Id region
1 1
2 2
3 3
4 4
5 5

Here users product's information  are inserted in House_p table and users inforamtion inserted on House_info table 

when page is load in my datalist show all product from House_p table 

and i bind dropdownlist from region table

here i want when users select their region from dropdown list  in datalist show product that are in selected region according to house_info table

now when i select region from dropdown list

EX: i select 1

 in my datalist in first page show all product that are in region=1

 problem is :when i click on other page of my datalist it showed all product that are in House_p table but i want it showed product that related to my selected item from dropdownlist i means first page is enough i don't want after showing product related

sp

ALTER PROCEDURE [dbo].[GetProducts] (
@Region tinyint = 0
)
AS
BEGIN
SET NOCOUNT ON;
SELECT distinct House_Info.BehCode,

[Code] .....