GridView is Shacking when i clicked my add Button - devexpress

Question

When i Click add button My Grid is shacking.
the Button Id is="AddNewUnit"
If i click Add or Edit button my grid is shrinking and suddenly comeback to normal size for 1st time only.
If the page is refresh again same problem is doing.
I dont know how to solve the problem.
If any body know the problem. Let me know.
<dx:ASPxCallbackPanel runat="server" ID="CallbackPanel" ClientInstanceName="CallbackPanel" >
<PanelCollection>
<dx:PanelContent ID="PanelContent3" runat="server">
<dx:ASPxButton ID="AddNewUnit" ClientInstanceName="AddNewUnit" runat="server" Text="Add New" OnInit="AddNewUnit_Init" Image-Url="~/App_Themes/Images/add.png"
AutoPostBack="false">
<ClientSideEvents Click="function(s, e) {Grdview.AddNewRow(); }" />
<Image Url="~/App_Themes/Images/add.png"></Image>
</dx:ASPxButton>
<dx:ASPxLabel ID="lblindex" ClientInstanceName="lblindex" runat="server" ClientVisible="false"></dx:ASPxLabel>
<dx:ASPxGridView ID="Grdview" ClientInstanceName="Grdview" runat="server" OnRowDeleting="Grdview_RowDeleting"
KeyFieldName="Id" AutoGenerateColumns="False" Width="100%" OnRowInserting="Grdview_RowInserting"
OnRowUpdating="Grdview_RowUpdating" OnCellEditorInitialize="Grdview_CellEditorInitialize">
<ClientSideEvents CustomButtonClick="custombuttonclicks" />
<Columns>
<dx:GridViewCommandColumn VisibleIndex="0" Caption="Edit" Width="6%" Name="EditButton" ShowEditButton="true">
<HeaderStyle HorizontalAlign="Center" VerticalAlign="Middle" Font-Bold="True"></HeaderStyle>
<CellStyle HorizontalAlign="Center" VerticalAlign="Middle"></CellStyle>
</dx:GridViewCommandColumn>
<dx:GridViewCommandColumn ShowNewButton="true" Name="Delete" ShowEditButton="false" VisibleIndex="1" ButtonType="Image"
Width="6%" Caption="Delete">
<HeaderStyle HorizontalAlign="Center" VerticalAlign="Middle" Font-Bold="True"></HeaderStyle>
<CellStyle HorizontalAlign="Center" VerticalAlign="Middle"></CellStyle>
<CustomButtons>
<dx:GridViewCommandColumnCustomButton ID="deluser">
<Image ToolTip="Delete" Url="App_Themes/Images/delete.png" Width="22px" Height="22px" />
</dx:GridViewCommandColumnCustomButton>
</CustomButtons>
<HeaderStyle Wrap="True" Font-Bold="True"></HeaderStyle>
</dx:GridViewCommandColumn>
<dx:GridViewDataTextColumn FieldName="Name" VisibleIndex="1" Width="14%" Settings-AutoFilterCondition="Contains"
Caption="Name">
<HeaderStyle HorizontalAlign="Center" VerticalAlign="Middle" Font-Bold="True"></HeaderStyle>
<CellStyle HorizontalAlign="Left" VerticalAlign="Middle"></CellStyle>
<PropertiesTextEdit Width="250px">
<ValidationSettings ErrorDisplayMode="Text" ErrorTextPosition="Bottom">
<RequiredField IsRequired="True" ErrorText="Please enter the Name"></RequiredField>
</ValidationSettings>
</PropertiesTextEdit>
<Settings AutoFilterCondition="Contains"></Settings>
<EditFormSettings VisibleIndex="0" Caption="Name" />
</dx:GridViewDataTextColumn>
<dx:GridViewDataTextColumn FieldName="Age" Caption="Age" VisibleIndex="2" Width="10%" PropertiesTextEdit-MaxLength="50"
HeaderStyle-Font-Bold="true" CellStyle-HorizontalAlign="Left" PropertiesTextEdit-ValidationSettings-RequiredField-ErrorText="Please enter the No. Of Beds"
Settings-AutoFilterCondition="Contains">
<HeaderStyle HorizontalAlign="Center" VerticalAlign="Middle" Font-Bold="True"></HeaderStyle>
<CellStyle HorizontalAlign="Right" VerticalAlign="Middle"></CellStyle>
<PropertiesTextEdit Width="250px" ValidationSettings-ErrorDisplayMode="Text">
<Style HorizontalAlign="Right">
</Style>
<ValidationSettings ErrorTextPosition="Bottom">
<RequiredField IsRequired="true" />
<RegularExpression ValidationExpression="^\d*\.?\d*$" ErrorText="Age accepts only numbers" />
</ValidationSettings>
</PropertiesTextEdit>
<EditFormSettings VisibleIndex="2" Caption="Age" />
</dx:GridViewDataTextColumn>
<dx:GridViewDataMemoColumn FieldName="Country" Width="35%" VisibleIndex="3" Caption="Country"
Settings-AutoFilterCondition="Contains">
<HeaderStyle HorizontalAlign="Center" VerticalAlign="Middle" Font-Bold="True"></HeaderStyle>
<CellStyle HorizontalAlign="Left" VerticalAlign="Middle"></CellStyle>
<PropertiesMemoEdit Height="50px" Width="250px">
<ValidationSettings ErrorDisplayMode="Text" ErrorTextPosition="Bottom">
<RequiredField IsRequired="True" ErrorText="Please enter the Country" />
</ValidationSettings>
</PropertiesMemoEdit>
<EditFormSettings VisibleIndex="3" Caption="Country" />
</dx:GridViewDataMemoColumn>
<dx:GridViewDataMemoColumn FieldName="State" Width="35%" VisibleIndex="4" Caption="State"
Settings-AutoFilterCondition="Contains">
<HeaderStyle HorizontalAlign="Center" VerticalAlign="Middle" Font-Bold="True"></HeaderStyle>
<CellStyle HorizontalAlign="Left" VerticalAlign="Middle"></CellStyle>
<PropertiesMemoEdit Height="50px" Width="250px">
<ValidationSettings ErrorDisplayMode="Text" ErrorTextPosition="Bottom">
<RequiredField IsRequired="True" ErrorText="Please enter the State" />
</ValidationSettings>
</PropertiesMemoEdit>
<EditFormSettings VisibleIndex="4" Caption="State" />
</dx:GridViewDataMemoColumn>
</Columns>
<SettingsCommandButton ApplyFilterButton-ButtonType="Button" ApplyFilterButton-Styles-FocusRectStyle-VerticalAlign="Middle">
<EditButton ButtonType="Image" Image-Height="24px" Image-Width="24px" Image-Url="App_Themes/Images/blueedit.png" Image-ToolTip="Edit">
<Image ToolTip="Edit" Height="24px" Width="24px" Url="App_Themes/Images/blueedit.png"></Image>
</EditButton>
<CancelButton ButtonType="Button" Styles-Style-VerticalAlign="Middle" Styles-Style-HorizontalAlign="Center" Image-ToolTip="Close Edit Form Without Saving Changes" Image-Width="60px">
<Image ToolTip="Close Edit Form Without Saving Changes" Width="60px"></Image>
<Styles>
<Style HorizontalAlign="Center" VerticalAlign="Middle"></Style>
</Styles>
</CancelButton>
<ShowAdaptiveDetailButton ButtonType="Image"></ShowAdaptiveDetailButton>
<HideAdaptiveDetailButton ButtonType="Image"></HideAdaptiveDetailButton>
<ApplyFilterButton ButtonType="Button" RenderMode="Button">
<Styles>
<FocusRectStyle VerticalAlign="Middle"></FocusRectStyle>
</Styles>
</ApplyFilterButton>
<UpdateButton ButtonType="Button" Styles-Style-VerticalAlign="Middle" Styles-Style-HorizontalAlign="Center" Image-ToolTip="Saving Changes." Image-Width="60px">
<Image ToolTip="Saving Changes." Width="60px"></Image>
<Styles>
<Style HorizontalAlign="Center" VerticalAlign="Middle"></Style>
</Styles>
</UpdateButton>
</SettingsCommandButton>
<SettingsEditing EditFormColumnCount="2" Mode="PopupEditForm">
</SettingsEditing>
<SettingsPager Mode="ShowPager" AlwaysShowPager="true" PageSize="10" Position="Bottom">
<PageSizeItemSettings Visible="true" Caption="Units to display" Items="5, 10, 25, 50" />
</SettingsPager>
<Settings ShowFilterRow="true" ShowFilterRowMenu="true" VerticalScrollBarMode="Visible" VerticalScrollableHeight="432" />
<SettingsPopup>
<EditForm Width="760px" HorizontalAlign="WindowCenter" VerticalAlign="WindowCenter" Modal="true" />
</SettingsPopup>
<Settings ShowTitlePanel="false" />
<SettingsText Title="Add New" PopupEditFormCaption="Edit" />
</dx:ASPxGridView>
</dx:PanelContent>
</PanelCollection>
</dx:ASPxCallbackPanel>
<dx:ASPxPopupControl ID="PopupforCustDeletePopupSubmitConfirmation" runat="server" ShowPageScrollbarWhenModal="true" PopupHorizontalAlign="WindowCenter" PopupVerticalAlign="WindowCenter" ClientInstanceName="PopupforCustDeletePopupSubmitConfirmation" AllowDragging="false" AllowResize="false" HeaderText="Alert"
EnableHotTrack="False" HeaderStyle-Font-Bold="true" CloseAction="CloseButton" Modal="True" HeaderStyle-HorizontalAlign="Left">
<ContentCollection>
<dx:PopupControlContentControl ID="PopupControlContentControl1" runat="server">
<dx:ASPxPanel ID="ASPxPanel1" runat="server" DefaultButton="btOK">
<PanelCollection>
<dx:PanelContent ID="PanelContent2" runat="server">
<table style="width: 400px">
<tr>
<td align="center">
<dx:ASPxLabel ID="lblCustDeletePopupConfirmationMsg" ViewStateMode="Disabled" runat="server" Text="Are you sure you want to delete the Unit?">
</dx:ASPxLabel>
</td>
</tr>
</table>
</dx:PanelContent>
</PanelCollection>
</dx:ASPxPanel>
<br />
<br />
<table style="width: 100px; margin: auto;">
<tr>
<td align="center" style="width: 50px">
<dx:ASPxButton ID="btnCustDeletePopupYes" runat="server" Text="Yes" Width="55px" AutoPostBack="false" ToolTip="Yes">
<ClientSideEvents Click="CustDeletePopupYes_Click" />
</dx:ASPxButton>
</td>
<td align="center" style="width: 49px; padding-left: 5px;">
<dx:ASPxButton ID="btnCustDeletePopupNo" runat="server" Text="No" AutoPostBack="false" Width="55px" ToolTip="No">
<ClientSideEvents Click="CustDeletePopupNo_Click" />
</dx:ASPxButton>
</td>
</tr>
</table>
</dx:PopupControlContentControl>
</ContentCollection>
<HeaderStyle>
<Paddings PaddingRight="6px"></Paddings>
</HeaderStyle>
<SizeGripImage Height="16px" Width="16px">
</SizeGripImage>
</dx:ASPxPopupControl>
My Screenshot attached Here

Answer 1

<dx:ASPxFormLayout ID="ASPxFormLayout1" runat="server"></dx:ASPxFormLayout>
<dx:ASPxPopupControl ID="ASPxPopupControl1" runat="server"></dx:ASPxPopupControl>
before aspxcallbackpanel paste it never shake.