image button click problem

m stuck in a very starnge proglem..

i hav a imagebutton in on which i have onClientClick and onclick both events lke

<asp:ImageButton ID="AddToFavroitImageButton" runat="server" ImageUrl="~/Images/etls/btn_Add2Favorite.png"

OnClientClick="switchid('AddFavDiv'); return true;" OnClick=&q ...