asp IE直接打印 只能打印几个字母 是怎么回事？

<script language="javascript" type="text/javascript">
    function preview() {
        bdhtml = window.document.body.innerHTML;
        sprnstr = "<!--startprint-->";
        eprnstr = "<!--endprint-->";
        prnhtml = bdhtml.substr(bdhtml.indexOf(sprnstr) + 17);
        prnhtml = prnhtml.substring(0, prnhtml.indexOf(eprnstr));
        window.document.body.innerHTML = prnhtml;
        window.print();
    }
</script><!--startprint-->
    <div id="note" class="utList">
        <asp:GridView ID="gvList" runat="server" AutoGenerateColumns="False" Width="100%"
            DataKeyNames="QuantityName" BorderWidth="4px" BorderColor="White" GridLines="Vertical"
            OnRowCommand="gvList_RowCommand" OnRowDataBound="gvList_RowDataBound">
            <RowStyle CssClass="no1" />
            <Columns>
…………………………
   </tr>
                </table>
            </EmptyDataTemplate>
            <HeaderStyle CssClass="title" />
            <AlternatingRowStyle CssClass="no2" />
        </asp:GridView>
    </div>
    <!--endprint-->
打印页面只显示这几个字母：   "; eprnstr = "
是什么情况？