FULL OUTER Join Problem

Hello Everyone

I have a problem when I execute the query below then it displays which entry is within typed date parameters. For example, I type date parameters to display projects between 01/01/2012 and 01/01/2013. Then it gives me the projects which are within dates above. For instance, 

Project A has started02/02/2012 and terminated in05/05/2012 then the query displays this project. The only request is start date of the project must be within the range. For instance,

Project B has started 01/01/2010 and terminated in 05/05/2012 then query does not display the project.  My query is below. Please have a look whats wrong here. I want to display the projects whose at least one parameter within the date parameters not just the start dat as above.

Thanks in advance.

SELECT        OPENING.*,CLOSING.*
FROM            (SELECT       *
                          FROM            vw_RP_BC_SummaryLogFrom
                          WHERE        (dateMark_From = @a)) AS OPENING FULL OUTER JOIN
                             (SELECT        *
                               FROM            vw_RP_BC_SummaryLogTill
                               WHERE        (dateMark_Till = @b)) AS CLOSING ON OPENING.bcId_From = CLOSING.bcId_Till

KAdir