compare tables from different database(using DropDownList to select database and CheckBoxList to select table)

Hi friends,
I am new in asp.net(with C#)programming.
I have two DropDownList from which i can select database and
I have two CheckBoxList from which i can select table .

when i select any database from DropDownList1 then corresponding table names appear in CheckBoxList1.
similarly in DropDownList2....

PROBLEM is as follows.........
when i select table name from CheckBoxList1 and CheckBoxList2, then matching records from both selected tables (I can select multiple table also) should be displayed (using inner joine).

This query i executed in query analyzer, it is running successfully.
select DB1.dbo.Table1.Name, DB1.dbo.Table1.Phone from DB1.dbo.Table1 inner join DB2.dbo.Table2 on DB1.dbo.Table1.Phone=DB2.dbo.Table2.Phone

My job depend upon this solution...plz can u help me in asp.net(using C#)...
Thanks a lot...
Mujtaba

I have found the solution for the stated problem...............it is working....
we can use this following sql query to resolve the problem....

cmd=new SqlCommand("SELECT "+ (DropDownList1.SelectedValue.ToString()) +".dbo."+ (CheckBoxList1.SelectedItem.ToString()) +".Name , "+(DropDownList1.SelectedValue.ToString()) +".dbo."+ (CheckBoxList1.SelectedItem.ToString()) +".Phone FROM "+(DropDownList1.SelectedValue.ToString()) +".dbo."+ (CheckBoxList1.SelectedItem.ToString())+" LEFT JOIN "+(DropDownList2.SelectedValue.ToString()) +".dbo."+ (CheckBoxList2.SelectedItem.ToString())+" ON "+(DropDownList1.SelectedValue.ToString()) +".dbo."+ (CheckBoxList1.SelectedItem.ToString()) +".Phone="+(DropDownList2.SelectedValue.ToString()) +".dbo."+ (CheckBoxList2.SelectedItem.ToString()) +".Phone",con);

Here "Name" and "Phone" are column names of the tables.