asp.net c# Button outside UpdatePanel not working

I have an .aspx page with a btn outside an UpdatePanel which is not firing. Nothing is happening if I click on btnSec1 or btnSec2. I tried in another page without UpdatePanel and is working. How should it be done? Thanks

   
    

        

            
Test de verificare a cunostintelor - editeaza
        
        

            

                

                    
                
            
            

                

                    
                
            
        

        

            Sectiunea 1
        

        

            Sectiunea 2
        
        

        
            
                ..................
            
        

and code behind

protected void Page_Load(object sender, EventArgs e)
{
    if (Request.QueryString["Sectiune"] != null)
    {
        string sec = Request.QueryString["Sectiune"];
        if (sec == "Sec-1")
        {
            DivSec1.Visible = true;
            DivSec2.Visible = false;
        }
        else if (sec == "Sec-2")
        {
            DivSec1.Visible = false;
            DivSec2.Visible = true;
        }
        else
        {
            return;
        }
    }
}
protected void ShowSec1(object sender, EventArgs e)
{
    string t = "Sec-1";
    Response.Redirect("/AdminPages/AddData.aspx?Sectiune=" + t);
}
protected void ShowSec2(object sender, EventArgs e)
{
    string t = "Sec-2";
    Response.Redirect("/AdminPages/AddData.aspx?Sectiune=" + t);
}