use confirm Box in aspx.cs page

$.get("Example.aspx?parameter1=1¶meter=2¶meter3=3, function(response) {
	               if(response!=null)
	               {
	               alert("Give yor msg here...");
confirm("msg"); 
	               }
	                        
	                    });

Response.Expires = -1;
        //required to keep the page from being cached on the client's browser
        string retResponse = String.Empty;

        
            string str= Request["parameter1"].ToString();
            string str1= Request["parameter2"].ToString();
            
            retResponse = functionName(str, str1);

        Response.ContentType = "text/plain";
        Response.Write(retResponse);
        Response.End();