Checkbox Only Records Value Of 1 To DB Table

<asp:CheckBox ID="chkName" Checked='<%#Bind("FirstName_Disp")%>' runat="server" />

<asp:SqlDataSource ID="srcProfile" runat="server" ConnectionString="<%$ ConnectionStrings:webConn %>"
    SelectCommand="sp_Profile_Get" SelectCommandType="StoredProcedure"
    DeleteCommand="sp_Profile_Delete" DeleteCommandType="StoredProcedure"
    UpdateCommand="sp_Profile_Update" UpdateCommandType="StoredProcedure">
    <SelectParameters>
        <asp:SessionParameter Name="UserID" SessionField="NewUserID" />
    </SelectParameters>
    <DeleteParameters>
        <asp:Parameter Name="UserID" />
    </DeleteParameters>
    <UpdateParameters>
       <asp:Parameter Name="UserID" />
****

<asp:Parameter Name="Name_Disp" Type="Byte" />

****</UpdateParameters>
</asp:SqlDataSource> 

 ALTER PROCEDURE dbo.sp_Profile_Update
@UserID uniqueidentifier,
****
@Email_Disp tinyint
****
AS

UPDATE [tbl****]
SET ****
Email_Disp = @Email_Disp
****
WHERE UserID = CONVERT(uniqueidentifier,@UserID)
 Above is a sample of a checkbox that users on my site can check/uncheck so that certain information will/will not display to other users. However, the only value that writes to the DB table--depending if it is checked or unchecked--is a 1 (checked). In a previous iteration of the page, it worked so I know it can be done but I didn't save the method. Any suggestions?