insert parameter for object data source - is DropDownList selected item??

hi folks,


I have a drop down list binded to object data source which  shows data from a table  called "Campaigns"
Campaigns table
CampaignId
CampaignName
ClientId

i have made the ddl  text value "CampaignName" but I want to insert
the value (campaignId) as the insert parameter in object data source?

The DDL is placed within a modal pop up extender which is opened using
a command like below
<asp:UpdatePanel ID="UpdatePanelModel"                                   runat="server" UpdateMode="Conditional">                  &nbs ...