<TABLE id="Tab4le1" height="100%" cellSpacing="2" cellPadding="2" width="100%">
                            <tr>
                                <td vAlign="top" id="m_printpage"><cr:crystalreportviewer id="crvMainView" runat="server" Width="350px" Height="50px" DisplayGroupTree="False" DisplayToolbar="False" EnableDrillDown="False"></cr:crystalreportviewer></td>
                            </tr>
                        </TABLE>

btnPrint.Attributes.Add("onclick", "printpage('m_printpage');");

        <script language="javascript">
            function printpage(m_printpage1){
                var newstr = document.all.item(m_printpage1).innerHTML;
                var oldstr = document.body.innerHTML;
                document.body.innerHTML = newstr;
                window.print(); 
                document.body.innerHTML = oldstr;
                return true;
            }
            function showHtml(obj)
            {
                obj.value = document.all.item("m_printpage").innerHTML;
            }
        </script>