LinkButton Click Event is not working in DetailsView

I have been struggling with asp.net DetailsViews for a while, and try to figure out why asp.net LinkButton Click Event doesn't fire inside of detailsview:

See my code below:

<asp:DetailsView 
    ID="detailsview1" 
    runat="server" 
    GridLines="Vertical"  
    AutoGenerateRows="False" 
    HeaderStyle-BackColor="#FFFFFF"
    HeaderStyle-ForeColor="White" 
    CellPadding="3" Height="50px" 
    Width="446px" 
    DataKeyNames="StoreNumber"
    BackColor="White" 
    BorderColor="#cccccc" 
    BorderStyle="None"  
    BorderWidth="1px" 
    ForeColor="Black"
    CommandRowStyle-Font-Overline="true">

<Fields>
    <asp:TemplateField HeaderText="Store Number:" HeaderStyle-Font-Names ="Tahoma">
    <ItemTemplate>
    <asp:Label ID="lblStoreNum" ForeColor ="#ff3300" runat="server" Text='<%# Bind("StoreNumber")%>'></asp:Label>
    </ItemTemplate>
        <HeaderStyle Font-Names="Tahoma" />
    </asp:TemplateField>

<asp:TemplateField  HeaderText ="View Image">
<ItemTemplate>                                                                    
<asp:LinkButton ID="LinkButton1" runat="server" ToolTip ="View Image" CommandName="storage"  CommandArgument='<%# Eval("StoreNumber")%>' onCommand="OpenViewPdf_Command"  >
<asp:Image ID="Image4" runat="server" ImageUrl="~/Images/viewImg_.png" ImageAlign ="Middle" Width ="20" Height="15" style="border-width: 0px; margin-left : 25px"/></asp:LinkButton>
</ItemTemplate>                                                            
<HeaderStyle Font-Bold="False" Font-Names="tahoma" Font-Size="9pt" Width ="75px" />
<ItemStyle Font-Bold="False" Font-Names="tahoma" Font-Size="9pt" Width ="75px" />
</asp:TemplateField> 

<asp:TemplateField HeaderText="First Name:" HeaderStyle-Font-Names ="Tahoma">
    <ItemTemplate>
    <asp:Label ID="lblFName" ForeColor ="#ff3300" runat="server" Text='<%# Bind("FirstName")%>'></asp:Label>
    </ItemTemplate>
        <HeaderStyle Font-Names="Tahoma" />
    </asp:TemplateField> 

<asp:TemplateField HeaderText="Last Name:" HeaderStyle-Font-Names ="Tahoma">
    <ItemTemplate>
    <asp:Label ID="lblLName" ForeColor ="#ff3300" runat="server" Text='<%# Bind("LastName")%>'></asp:Label>
    </ItemTemplate>
        <HeaderStyle Font-Names="Tahoma" />
    </asp:TemplateField> 

</Fields>
    <FooterStyle BackColor="#CCCCCC" />
    <HeaderStyle BackColor="Black" Font-Bold="True" ForeColor="White" />
    <PagerStyle BackColor="#999999" ForeColor="Black" HorizontalAlign="Center" />
</asp:DetailsView>

Protected Sub OpenViewPDF_Command(sender As Object, e As CommandEventArgs)

 Dim StoreNumber As String = txtStoreNumber.Text.Trim()
 Dim storenumber = e.CommandArgument 
      if e.commandName = "storage" then       
        ScriptManager.RegisterStartupScript(Me, Me.GetType(), "key", "window.open('http://ABC/files/ & storeNumber & ".pdf','_blank');", True)
        End If
    End Sub

I would like the linkbutton clickEvent to work in detailsview.

Your help is much appreciated.

Thank you.