母版页里设定如下：

<table>
                    <tr>
                        <td>
                            <asp:LinkButton ID="lbtnIndex" runat="server" CssClass="MenuLink" OnClick="lbtnIndex_Click">
                                <asp:Panel ID="pnlIndex" runat="server">
                                </asp:Panel>
                            </asp:LinkButton>
                        </td>
                        <td>
                            <asp:LinkButton ID="lbtnMyOrder" runat="server" CssClass="MenuLink" OnClick="lbtnMyOrder_Click">
                                <asp:Panel ID="pnlMyOrder" runat="server">
                                </asp:Panel>
                            </asp:LinkButton>
                        </td>
                        <td>
                            <asp:LinkButton ID="lbtnMyAccount" runat="server" CssClass="MenuLink" OnClick="lbtnMyAccount_Click">
                                <asp:Panel ID="pnlMyAccount" runat="server">
                                </asp:Panel>
                            </asp:LinkButton>
                        </td>
                        <td>
                            <asp:LinkButton ID="lbtnCancel" runat="server" CssClass="MenuLink" OnClick="lbtnCancel_Click">
                                <asp:Panel ID="pnlCencel" runat="server">
                                </asp:Panel>
                            </asp:LinkButton>
                        </td>
                    </tr>

</table>

引用母版页里在page_load里面写上如下代码：

 ((Panel)Master.FindControl("pnlIndex")).CssClass = "Nav_index_No";
                ((Panel)Master.FindControl("pnlMyOrder")).CssClass = "Nav_MOrder";
                ((Panel)Master.FindControl("pnlMyAccount")).CssClass = "Nav_MAccount_No";
                ((Panel)Master.FindControl("pnlCencel")).CssClass = "Nav_Back_No";

具体的样式如下：

.Nav_index
{
 height: 52px;
 width: 111px;
 margin-top: 22px;
 
 padding-top: 19px;
 background-image: url(../../../image/OnlinePrint/index_ha.jpg);
 background-repeat: no-repeat;
 margin-top: 22px !important;
 
}
.Nav_index_No
{
 height: 52px;
 width: 111px;
 margin-top: 22px;
 padding-top: 22px;
 background-image: url(../../../image/OnlinePrint/index_hui.jpg);
 background-repeat: no-repeat;
 margin-top: 24px !important;
}

.Nav_MOrder
{
 height: 52px;
 width: 111px;
 margin-top: 22px;
 padding-top: 19px;
 background-image: url(../../../image/OnlinePrint/Morder_ha.jpg);
 background-repeat: no-repeat;
 margin-top: 22px !important;
}
.Nav_MOrder_No
{
 height: 52px;
 width: 111px;
 margin-top: 22px;
 padding-top: 22px;
 background-image: url(../../../image/OnlinePrint/Morder_hui.jpg);
 background-repeat: no-repeat;
 margin-top: 24px !important;
}

.Nav_MAccount
{
 height: 52px;
 width: 111px;
 margin-top: 22px;
 padding-top: 19px;
 background-image: url(../../../image/OnlinePrint/MAccount_ha.jpg);
 background-repeat: no-repeat;
 margin-top: 22px !important;
}
.Nav_MAccount_No
{
 height: 52px;
 width: 111px;
 margin-top: 26px;
 padding-top: 22px;
 background-image: url(../../../image/OnlinePrint/MAccount_hui.jpg);
 background-repeat: no-repeat;
 margin-top: 24px !important;
}

.Nav_Back_No
{
 height: 52px;
 width: 111px;
 margin-top: 26px;
 padding-top: 22px;
 background-image: url(../../../image/OnlinePrint/Back_hui.jpg);
 background-repeat: no-repeat;
 margin-top: 24px !important;
}