Hi 
Experts
I am facing the following issue

Microsoft JScript runtime error: Sys.InvalidOperationException: Handler was not added through the Sys.UI.DomEvent.addHandler method. 

I am having a Grid that is filled with Locations.To add locations i am using ajaxmodalpopup.when i click on add location imagebutton in gridview footer the popup is working fine.but when i press F5 while popup is opened i am getting the issue.
here is the sample code

CellPadding="4" GridLines="None" ShowFooter="True" OnRowCancelingEdit="gdvLocations_RowCancelingEdit"
OnRowEditing="gdvLocations_RowEditing" OnRowDeleting="gdvLocations_RowDeleting"
OnRowUpdating="gdvLocations_RowUpdating" OnRowDataBound="gdvLocations_RowDataBound"
OnPreRender="gdvLocations_PreRender" Width="98%" EnableModelValidation="false">


SortExpression="BusinessEntityID" Visible="False">

Text='<%# Eval("ID") %>'>


SortExpression="LocationId">

Text='<%# Eval("SerialNumber") %>'>



SortExpression="LocationName">

Text='<%# Eval("ChildEntityName") %>'>
ErrorMessage="*" ValidationGroup="EditRow">


meta:resourcekey="txtfooterLocationNameResource1">
meta:resourcekey="rfvLocationName" ValidationGroup="SecondRow">



Text='<%# Eval("ChildEntityName") %>' Width="120">




meta:resourcekey="TemplateFieldResource8" SortExpression="Address">

ReadOnly="True" Text='<%# Eval("AddressDetails") %>'>
meta:resourcekey="rfvAddressEdit" ValidationGroup="EditRow">
CommandName="EditAddress" ToolTip="Add Address" ImageUrl="~/Assets/Images/add.png"
meta:resourcekey="ibtnEditAddressResource1" OnClick="EditAddress_Click" Style="background: none;" />


ReadOnly="True">
meta:resourcekey="rfvAddress" ValidationGroup="SecondRow">
ImageUrl="~/Assets/Images/add.png" meta:resourcekey="ibtnAddAddress" OnClick="ibtnAddAddressNoData_Click"
Style="background: none;" />



Text='<%# Eval("AddressDetails") %>'>




DeleteText="Delete" CausesValidation="true" ValidationGroup="EditRow" HeaderText="Actions"
ShowEditButton="True" ShowDeleteButton="True">




OnClick="lnkInsertLocation_Click" ValidationGroup="SecondRow">
























Location Name

Address

Actions


meta:resourcekey="rfvLocation" ValidationGroup="firstrow">


meta:resourcekey="rfvAddress" ValidationGroup="firstrow">
ImageUrl="~/Assets/Images/add.png" meta:resourcekey="ibtnAddAddressNoData" OnClick="ibtnAddAddressNoData_Click"
Style="background: none;" />

OnClick="NoDataInsert_Click" ValidationGroup="firstrow">











Style="display: none;">












CssClass="inputLabel">


*
ValidationGroup="AddAddressDetails" Display="Dynamic" meta:resourcekey="rfvStreetNumberForLocation"
ForeColor="Red">

meta:resourcekey="regStreetNumberForLocation" ValidationExpression="^[-;:,0-9a-zA-Z./ ]+$"
Display="Dynamic" SetFocusOnError="true">



CssClass="inputLabel">


*
ValidationGroup="AddAddressDetails" Display="Dynamic" meta:resourcekey="rfvStreetNameForLocation"
ForeColor="Red">
meta:resourcekey="regStreetNameForLocation" ValidationExpression="^[-;:,0-9a-zA-Z./ ]+$"
Display="Dynamic" SetFocusOnError="true">


CssClass="inputLabel">

ControlToValidate="txtSuiteAppartmentForLocation" meta:resourcekey="regSuiteAppartmentForLocation"
ValidationExpression="^[0-9a-zA-Z ]+$" Display="Dynamic" SetFocusOnError="true">






id="spanCityForLocation" runat="server" style="color: Red; font-weight: bold;
font-size: 18px;">*
ValidationGroup="AddAddressDetails" Display="Dynamic" meta:resourcekey="rfvCityForLocation"
ForeColor="Red">
ValidationExpression="^[a-zA-Z ]+$" Display="Dynamic" SetFocusOnError="true"
meta:resourcekey="regCityForLocation">


CssClass="inputLabel">


*
ControlToValidate="ddlStateForLocation" ValidationGroup="AddAddressDetails" Display="Dynamic"
meta:resourcekey="rfvStateForLocation" ForeColor="Red" SetFocusOnError="true">





































*


ValidationGroup="AddAddressDetails" Display="Dynamic" ForeColor="Red" meta:resourcekey="rfvZipForLocation"
InitialValue="Select">



Text="Search" OnClick="btnGetMatchingAddress_Click" />
CausesValidation="false" meta:resourcekey="btnCancelResource1" OnClick="btnAddMoreDetailsCancel_Click" />



BorderColor="#c7d5de" BorderWidth="1" CssClass="policyInfo" Width="830px" AllowPaging="True"
OnPageIndexChanging="gdvEpassmatchedAddress_PageIndexChanging" EnableViewState="true"
PageSize="5" EmptyDataText="No Records Found">



EnableViewState="true" GroupName="checkAddress" onclick="RadioCheckForMatching(this);"
OnCheckedChanged="rdbtnMatching_CheckedChanged" />







ItemStyle-HorizontalAlign="Center" ItemStyle-VerticalAlign="Middle">



































CssClass="btnBand-Grn" CausesValidation="false" OnClick="btnValidAndAssign_Click" />



















Style="display: none;" />
TargetControlID="btnmoreDetails" PopupControlID="pnlAddressDetails" CancelControlID="btnCancel"
Enabled="True" DynamicServicePath="">


help me plz