<web:cImageButton ID="btnAbc"  OnClick = btnAbc_Click" runat="server"  CommandName="Export" 
                CommandArgument='<%#Eval("Codice") %>' ImageUrl="~/images/pippo.gif" 
                                    CssClass="button"  />
                                    
                     <web:cImageButton ID="btnDef"  OnClick = "btnDef_Click" runat="server"  CommandName="Export" 
                CommandArgument='<%#Eval("Codice") %>' ImageUrl="~/images/pluto.gif" 
                                    CssClass="button" />

<asp:ImageButton ID="btnShow" CommandArgument='<%#Eval("Codice") %>'
                                CausesValidation="false" runat="server" 
                                ImageUrl="~/Images/paperino.gif"/>