RadGrid with modal popup

[Wayne]

I have a radgrid with a standard modal popup for making entries.  Everything works as it should.  However, I have been trying to modify the field in the popup window so the user would see a multiline box to make entries. 

I've tried css, asp:textbox,  and other ideas. but they all failed.  Here is my code..... 

any help would be appriciated. 

<div style="width:95%; margin:2%; display:inline-block">
                        <telerik:RadGrid ID="RadGrid1" runat="server" OnNeedDataSource="RadGrid1_NeedDataSource" AutoGenerateColumns="False"
                            CellSpacing="-1" GridLines="Both" RenderMode="Lightweight" OnItemCommand="RadGrid1_ItemCommand" MasterTableView-ExpandCollapseColumn-CommandName="Insert">
                        <GroupingSettings CollapseAllTooltip="Collapse all groups" />
                        <MasterTableView CommandItemDisplay="Top" EditFormSettings-PopUpSettings-Modal="true" EditMode="PopUp" DataKeyNames="Line">
                            <CommandItemSettings ShowSaveChangesButton="False" />
                            <RowIndicatorColumn ShowNoSortIcon="False" Visible="False">
                            </RowIndicatorColumn>
                            <ExpandCollapseColumn Created="True" ShowNoSortIcon="False">
                            </ExpandCollapseColumn>
                            <Columns>
                                <telerik:GridBoundColumn DataField="Line" ReadOnly="true" FilterControlAltText="Filter Line column" HeaderText="Line" ShowNoSortIcon="False" UniqueName="Line">
                                    <HeaderStyle Width="15px" HorizontalAlign="Center" /> 
                                    <ItemStyle CssClass="lineNo" />
                                </telerik:GridBoundColumn>
                                <telerik:GridBoundColumn DataField="Description" ReadOnly="false" FilterControlAltText="Filter Description column" HeaderText="Description" ShowNoSortIcon="False" UniqueName="Description">
                                    <HeaderStyle Width="50%" />
                                    <ItemStyle CssClass="description" />
                                </telerik:GridBoundColumn>
                                <telerik:GridBoundColumn DataField="Created_by" ReadOnly="true" FilterControlAltText="Filter Created_by column" HeaderText="Created By" ShowNoSortIcon="False" UniqueName="Created_by">
                                    <HeaderStyle Width="10%" />
                                    <ItemStyle CssClass="empNo" />
                                </telerik:GridBoundColumn>
                                <telerik:GridBoundColumn DataField="Created_Name" ReadOnly="true" FilterControlAltText="Filter Created_by column" HeaderText="Created Name" ShowNoSortIcon="False" UniqueName="Created_Name">
                                    <HeaderStyle Width="20%" />
                                    <ItemStyle CssClass="empName" />
                                </telerik:GridBoundColumn>
                                <telerik:GridBoundColumn DataField="Created_Date" ReadOnly="true" FilterControlAltText="Filter Created_Date column" HeaderText="Created Date" ShowNoSortIcon="False" UniqueName="Created_Date">
                                    <HeaderStyle Width="15%" />
                                </telerik:GridBoundColumn>
                            </Columns>
                            <EditFormSettings InsertCaption="Add new item" CaptionFormatString="Edit Line: {0}" CaptionDataField="Line">
                                <EditColumn FilterControlAltText="Filter EditCommandColumn column">
                                </EditColumn>
                                <PopUpSettings Modal="True" />
                            </EditFormSettings>
                        </MasterTableView>
                        <FilterMenu RenderMode="Lightweight">
                        </FilterMenu>
                        <HeaderContextMenu RenderMode="Lightweight">
                        </HeaderContextMenu>
                    </telerik:RadGrid>

                    </div>