Image.Visible is always false

protected void Page_Load(object sender, EventArgs e)
   {
       Page.Form.Attributes.Add("enctype", "multipart/form-data");
   }

protected void btnUpdate_Click(object sender, EventArgs e)
    {
        txtCatNum.Text=Grid.SelectedRow.Cells[1].Text;
        txtCantName.Text = Grid.SelectedRow.Cells[2].Text;
        txtDescription.Text = Grid.SelectedRow.Cells[3].Text;
        txtCatNum.ReadOnly = true;
        ImgUPAdd.Visible = true;
        ImgUPAdd.ImageUrl = "../../CatImgs"+txtCatNum.Text+"jpg";
        MultiView1.ActiveViewIndex = 1;
    }

protected void btnAdd_Click(object sender, EventArgs e)
   {
       MultiView1.ActiveViewIndex = 1;
       txtCantName.Text = "";
       txtCatNum.Text = "";
       txtDescription.Text = "";
      ImgUPAdd.Visible = false;
       txtCatNum.ReadOnly = false;
       txtCatNum.Text = Cat.GetNextCatNo();
   }

<asp:ScriptManager ID="ScriptManager1" runat="server">

<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<Triggers>
<asp:PostBackTrigger ControlID="btnSave" />
</Triggers>

<br />
<asp:MultiView ID="MultiView1" runat="server" ActiveViewIndex="0">
<br />
<asp:View ID="View1" runat="server">
<table align="center" cellpadding="3" cellspacing="4" class="style1" dir="ltr">
<tr>
<td class="style3">
                                                 
<asp:Label ID="Label1" runat="server" Font-Names="Impact" Font-Size="Large" 
Text="Search Products Categories">
                                                     
</td>
</tr>
<tr>
<td class="style3">
 <asp:Label ID="Label2" runat="server" Font-Names="Impact" Font-Size="Large" 
style="text-align: left" Text="search by:">
<asp:RadioButtonList ID="rdoField" runat="server" RepeatDirection="Horizontal">
<asp:ListItem Selected="True" Value="CatNo">Category Number
<asp:ListItem Value="CatName">Category Name

</td>
</tr>
<tr>
<td class="style3">
<asp:Label ID="Label3" runat="server" Font-Names="Impact" Font-Size="Large" 
Text="Value to Search">
<asp:TextBox ID="TxtSearch" runat="server">
<asp:Button ID="BtnSearch" runat="server" Height="33px" Text="Search" 
Width="85px" onclick="BtnSearch_Click" />
</td>
</tr>
<tr>
<td class="style3">
<asp:Button ID="btnAdd" runat="server" onclick="btnAdd_Click" Text="Add Item" />
<asp:Button ID="btnUpdate" runat="server" Enabled="False" Text="Update" 
onclick="btnUpdate_Click" />
<asp:Button ID="BtnRemove" runat="server" Enabled="False" 
style="text-align: right" Text="Remove " onclick="BtnRemove_Click" />
</td>
</tr>
<tr>
<td class="style3">
<asp:Label ID="LblMessage" runat="server" ForeColor="#CC3300">
                                                        
</td>