Show Hide Table Row based on DropDownList using C# and VB.Net in ASP.Net

Hi kankon

Refer below sample code :

HTML

<div>Do you have Passport?
<asp:DropDownList ID="ddlHasPassport" runat="server" AutoPostBack="true" OnSelectedIndexChanged="DropDownList_Changed">
    <asp:ListItem Text="Please Select" Value="0" />
    <asp:ListItem Text="All" Value="1" />
    <asp:ListItem Text="January" Value="2" />
    <asp:ListItem Text="February" Value="3" />
    <asp:ListItem Text="March" Value="4" />
    <asp:ListItem Text="April" Value="5" />
</asp:DropDownList>
<hr />
<table>
    <tr>
        <th>Month</th>
        <th>Savings</th>
    </tr>
    <asp:Panel ID="pnlJan" runat="server" Visible="false">
        <tr>
            <th>January</th>
            <th>$100</th>
        </tr>
    </asp:Panel>
    <asp:Panel ID="pnlFeb" runat="server" Visible="false">
        <tr>
            <th>February</th>
            <th>$280</th>
        </tr>
    </asp:Panel>
    <asp:Panel ID="pnlMarch" runat="server" Visible="false">
        <tr>
            <th>March</th>
            <th>$860</th>
        </tr>
    </asp:Panel>
    <asp:Panel ID="pnlApril" runat="server" Visible="false">
        <tr>
            <th>April</th>
            <th>$86</th>
        </tr>
    </asp:Panel>
</table>
</div>

C# 

protected void DropDownList_Changed(object sender, EventArgs e)
{
    if (ddlHasPassport.SelectedItem.Value == "1")
    {
        pnlJan.Visible = true;
        pnlFeb.Visible = true;
        pnlMarch.Visible = true;
        pnlApril.Visible = true;
    }
    else
    {
        if (ddlHasPassport.SelectedItem.Value == "2")
        {
            pnlJan.Visible = true;
        }
        else
        {
            pnlJan.Visible = false;
        }
        if (ddlHasPassport.SelectedItem.Value == "3")
        {
            pnlFeb.Visible = true;
        }
        else
        {
            pnlFeb.Visible = false;
        }
        if (ddlHasPassport.SelectedItem.Value == "4")
        {
            pnlMarch.Visible = true;
        }
        else
        {
            pnlMarch.Visible = false;
        }
        if (ddlHasPassport.SelectedItem.Value == "5")
        {
            pnlApril.Visible = true;
        }
        else
        {
            pnlApril.Visible = false;
        }
    }
}

VB.Net

Protected Sub DropDownList_Changed(ByVal sender As Object, ByVal e As EventArgs)
    If ddlHasPassport.SelectedItem.Value = "1" Then
        pnlJan.Visible = True
        pnlFeb.Visible = True
        pnlMarch.Visible = True
        pnlApril.Visible = True
    Else

        If ddlHasPassport.SelectedItem.Value = "2" Then
            pnlJan.Visible = True
        Else
            pnlJan.Visible = False
        End If

        If ddlHasPassport.SelectedItem.Value = "3" Then
            pnlFeb.Visible = True
        Else
            pnlFeb.Visible = False
        End If

        If ddlHasPassport.SelectedItem.Value = "4" Then
            pnlMarch.Visible = True
        Else
            pnlMarch.Visible = False
        End If

        If ddlHasPassport.SelectedItem.Value = "5" Then
            pnlApril.Visible = True
        Else
            pnlApril.Visible = False
        End If
    End If
End Sub

Screenshot