sorry for that, i m practicing for my exam and in that form there is only one textbox and three labels and i can remember them so i don't feel to name them properly. But i didn't your point, how i can solve this problem. i tried below code but could not done...

private void button2_Click(object sender, EventArgs e)
        {
            student.CourseRegistered = checkedListBox1.CheckedItems.Count;
            foreach (Courses course in StaticData.coursesList) 
            {
                if (course == checkedListBox1.SelectedItem) 
                
                {
                    crss = course;
                    lst.Add(course.courseFee);
                }
                
            }


            foreach (int value in lst) 
            {
                student.Total_Fee += value;
            }
            MessageBox.Show(student.CourseRegistered.ToString());
        }

sorry last code is not complete i have also declared these globally

Courses crss = new Courses();
List<int> lst = new List<int>();

textbox1.text is the textbox where we enter student registration number that it will search and then change the label text with that searched student name. Button1 is search button, Button2 is for submit or course assigning button.

Thanks bro....
Thank you so much...

Friends tell me about it hurry up. Its my assignment