Button's PostBackURL not work after executing javascript.

Hello all,
I need your help!

 I added a Button and a  LinkButton to same page and set same properties to both of them. LinkButton works fine but Button's PostBackURL not work after executing javascript (Clicked "OK" in message window). it posted back to same page instead of second page. following is the code:


<asp:Button ID="Button1" runat="server" Text="Button"  
                PostBackUrl="~/second.aspx"
              OnClientClick="return confirm('Switch page?');" />

                
            
    <asp:LinkButton ID="LinkButton1& ...