Display Message(Saved Successfully) and Pass session to another page in ASP.Net

When i Pass Session in My Save Button  That time MY MessageBox Does Not Show my message (" Record Added SucessFully !!! ")

(

cmd.ExecuteNonQuery();  ShowMessaage(" Record Added SucessFully !!!"); 

Session["LastName"] = txtlLName.Text;

Response.Redirect("Default2.aspx");

)

But It Shows Message When I Removed Session Passing Code

(

Session["LastName"] = txtlName.Text;

Response.Redirect("Default2.aspx");

)

Session Passing Code Removed then Message show Properly.

How can I Do ???

i want to Show Message And Then  I want to pass session On Save Button