Hi, Peter,
I fixed myself.
the correct one is
NavigateUrl='<%# DataBinder.Eval(Container.DataItem, "Professor_email", "mailto:{0}") %>'
Thanks anyway.
Ray

you can use "add new literalcontrol(hyperlink)" also

Hey, I need to make website links actual links within the datagrid. Not like email links ... http://... how do i do that... It is an editable datagrid.
below is the column i need it for

<asp:TemplateColumn HeaderText="Link">
                                    <ItemTemplate>
                                        <asp:Label id="lblSOURCE_LINK" runat="server" Text='<%# DataBinder.Eval(Container, "DataItem.SOURCE_LINK") %>'>
                                        </asp:Label>
                                    </ItemTemplate>
                                    <EditItemTemplate>
                                        <asp:TextBox id="txtSOURCE_LINK" runat="server" Text='<%# DataBinder.Eval(Container, "DataItem.SOURCE_LINK") %>'>
                                        </asp:TextBox>
                                    </EditItemTemplate>
                                </asp:TemplateColumn>



thanks a lot