Hi, Pungis,
You can achieve this using ASP.Nets AJAX Controls viz., UpdatePanel and UpdateProgress.
You need to put your controls in UpdatePanel and UpdateProgress
<asp:UpdateProgress runat="server" AssociatedUpdatePanelID="UpdatePanel1">
<ProgressTemplate>
<%-- Your .gif Image Or "Please Wait Text" --%>
</ProgressTemplate>
</asp:UpdateProgress>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<%-- Your othre controls Like DDL and so forth --%>
<asp:MultiView ID="MultiView1" runat="server" OnActiveViewChanged="MultiView1_ActiveViewChanged">
<asp:View ID="View1" runat="server">
THIS IS VIEW 1 .<br />
<br />
</asp:View>
</asp:MultiView>
</ContentTemplate>
</asp:UpdatePanel>
Above code is nothing but some basic skeliton for your needs, please modify the code above as per your need.
Thanks and Regards,
Rk_Hirpara