Retrieving bound data from a Gridview

I have a Gridview connected to a SQL datasource displaying data, and what I hope to do is retrieve data associated with a selected row through a button and Eval.

Somthing like,

<asp:LinkButton runat=server OnClientClick="RetrieveInfo" Text="Send" />

But I can't call Eval from code, and I don't know how to get the DataKey either.

I've been scouring the internet, but haven't found anything nice. Can anyone help me? Would be much appreciated.

EDIT:

<asp:GridView ID="GridView1" Width="100%" runat="server" AutoGenerateColumns="False"
DataKeyNames="ScheduleID" DataSourceID="SqlDataSource1">
    <Colums>
        <asp:TemplateField HeaderText="Date" SortExpression="Date">
           <ItemTemplate>
            <asp:Label ID="Label1" runat="server" Text='<%#Eval("Date")%>' />
          </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Time" SortExpression="starttime">
           <ItemTemplate>
            <asp:Label ID="Label1" runat="server" Text='<%#Eval("starttime")%>' />
          </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField>
           <ItemTemplate>
            <asp:LinkButton runat=server OnClientClick="RetrieveInfo" Text="Send" />
          </ItemTemplate>
        </asp:TemplateField>
    </Colums>
</asp:GridView>

It's skimmed, but that's basically it.