public void viewTopStudentList(object sender, EventArgs args)
        {
            List <int>    totalMarks = new List <int>();
            List <String> stdName    = new List <String>();

            Model.StdMarksRepo        repo  = new Model.StdMarksRepo();
            List <Model.StudentMarks> marks = repo.GetStudentsMarks();
            Dictionary <Model.StudentPersonal, int> tlMarks = new Dictionary <Model.StudentPersonal, int>();

            foreach (var item in marks)
            {
                if (item.Chemistry > 40 && item.Computing > 40 && item.English > 40 && item.Mathematics > 40 && item.Physics > 40)
                {
                    tlMarks.Add(item.StudentPersonal, (int)(item.Chemistry + item.Computing + item.English + item.Mathematics + item.Physics));
                }
            }

            foreach (var item in tlMarks)
            {
                totalMarks.Add(item.Value);
            }
            totalMarks.Sort();
            totalMarks.Reverse();

            var i = 0; 
 List <Model.StudentPersonal> stdId = new List <Model.StudentPersonal>();
            var count = 0; 
                 if (totalMarks.Count >= 3)

            {
                count = 3;
            }
            else
            {
                count = totalMarks.Count;
            } 
                      while (i < count)
            {
                
                              {
                    foreach (var item in tlMarks)
                    {
                        if (!totalMarks[i].Equals(null))
                        {
                            if (item.Value == totalMarks[i])
                            {
                                stdId.Add(item.Key);
                                Console.WriteLine(stdId[i]);
                            }
                        }
                    }
                    i++; 


                }
            }

            List <Model.StudentPersonal> stdPer = repo.GetStudents(); 
 int index = 0; 
                 while (index < stdId.Count)
            {
                
                    {
                    
                              foreach (var st in stdPer)
                    {
                        
                             {
                            if (st == stdId[index])
                            {
                                stdName.Add(st.FirstName + " " + st.LastName);
                                Console.WriteLine(stdName[index]);
                            }
                        }
                    }
                    
 index++; 


                }
            }
            

 headerStu.InnerText = "Top 3 Students"; 

 TableRow tr; 
 TableCell tc; 
 TableCell tc1;
            TableCell       tc2; 
 TableHeaderRow th = new TableHeaderRow(); 
 TableHeaderCell thc = new TableHeaderCell(); 
 TableHeaderCell thc1 = new TableHeaderCell();
            TableHeaderCell thc2 = new TableHeaderCell(); 
 thc.Text = "Student Name"; 
 th.Cells.Add(thc); 
 thc1.Text = "Obtained Marks"; 
 th.Cells.Add(thc1); 
 thc2.Text = "Total Marks";

            th.Cells.Add(thc2); 
 tblSample.Rows.Add(th); 



                     for (int a = 0; a < stdName.Count; a++)
            {
                
                        {
                    
 tr = new TableRow(); 
 tc = new TableCell(); 
 tc1 = new TableCell();

                    tc2 = new TableCell(); 
 tc.Text = stdName[a]; 
 tr.Cells.Add(tc); 
 tc1.Text = totalMarks[a].ToString(); 
 tr.Cells.Add(tc1);

                    tc2.Text = "500";
                    tr.Cells.Add(tc2); 
 tblSample.Rows.Add(tr); 


                }
            }
            


                

        }