am getting error with code  at the end false i text at false without ) or add 1 or 2x )) all error 

Server Error in '/' Application.

Parser Error

Description: An error occurred during the parsing of a resource required to service this request. Please review the following specific parse error details and modify your source file appropriately. Parser Error Message: The server tag is not well formed. Source Error:

Line 849:

Line 847:                <asp:TemplateField HeaderText="تاريخ الطلب">
Line 848:                    <ItemTemplate>
Line 849:                        <asp:Label ID="lblBoxDate3" runat="server" <%# String.Format("{0} - {1}", Eval("vacationdata", "{0:yyyy/MM/dd}"),  Visible= Eval("namevacation").ToString() == "اجازة دورية" ? true : false ) %>'></asp:Label>
Line 850:                    </ItemTemplate> 
Line 851:                  

                <asp:TemplateField HeaderText="تاريخ الطلب">
                    <ItemTemplate>
                        <asp:Label ID="lblBoxDate3" runat="server" <%# String.Format("{0} - {1}", Eval("vacationdata", "{0:yyyy/MM/dd}"),  Visible= Eval("namevacation").ToString() == "اجازة دورية" ? true : false %>'></asp:Label>
                    </ItemTemplate>                   
                    <EditItemTemplate>
                        <asp:TextBox ID="txtBoxDate3" runat="server" Text='<%# Eval("vacationdata", "{0:yyyy/MM/dd}") %>' TextMode="Date"></asp:TextBox>
                    </EditItemTemplate>                   
                    <ItemTemplate>
                        <asp:Label ID="lblBoxDate31" runat="server"  <%# String.Format("{0} - {1}", Eval("dateorder", "{0:yyyy/MM/dd}"),  Visible= Eval("namevacation").ToString() == "اقرار عودة" ? true : false ) %>'></asp:Label>
                    </ItemTemplate>
                    <EditItemTemplate>
                        <asp:TextBox ID="txtBoxDate31" runat="server" Text='<%# Eval("dateorder", "{0:yyyy/MM/dd}") %>' TextMode="Date"></asp:TextBox>
                    </EditItemTemplate>
                    <ControlStyle Width="70px" />
                    <ItemStyle Width="70px" HorizontalAlign="Center"></ItemStyle>
                </asp:TemplateField>