Accessing selected value from a masterpage/webpart control from the content page?

[jobs]

I have a master page with a webpart that contains a custom control with
a calendar in it.


The below content page complains that it knows nothing about Calendar1
which is of course somewhere else.

Thanks.



<SelectParameters>
<asp:ControlParameter ControlID="Calendar1" Name="Caldate"
PropertyName="SelectedDate" Type="DateTime" />
</SelectParameters>

</asp:SqlDataSource>

Any way to reference it in asp.net, or will have have to code that in
the codebehind? and if so how?

Thanks.