خطأ عند الضغط علي مفتاح حفظ

المشكلة اننا لما باجي اقف علي سجل معين ويتعرض بيانات هذا السجل علي التكستات وباجي اغير في تكست مثلا زي رقم الحساب بغيرة من 002 الي 004 وبظغط مفتاح حفظ بيظهر هذا الاعتراض علما بانني قمت بوضع مفتاح اساسي علي حقل Name

f1 = "'" & TextBox1.Text & "',"
		f2 = "'" & DateTimePicker1.Value & "',"
		f3 = "'" & ComboBox1.Text & "',"
		f4 = "'" & TextBox2.Text & "',"
		f5 = "'" & TextBox5.Text & "',"
		f6 = "'" & TextBox4.Text & "',"
		f7 = "'" & MaskedTextBox1.Text & "',"
		f8 = "'" & TextBox6.Text & "',"
		f9 = "'" & TextBox3.Text & "',"
		f10 = "'" & TextBox7.Text & "',"
		f11 = "'" & ComboBox3.Text & "',"
		f12 = "'" & ComboBox2.Text & "',"
		f13 = "'" & TextBox8.Text & "',"
		f14 = "'" & DateTimePicker2.Value & "',"
		f15 = "'" & DateTimePicker3.Value & "',"
		f16 = "'" & ComboBox4.Text & "',"
		f17 = "'" & TextBox9.Text & "',"
		f18 = "'" & TextBox10.Text & "'"
		s = "INSERT INTO Cust "
		s = s & "(Name,Birth_Date,Gender,Nationality,Fax,Tel,"
		s = s & "Mobile,Email,Adress,ID_Num,ID_Type,Work_type,"
		s = s & "Account_num,First_Date,Last_Date,"
		s = s & "Card_type,Maximum,Card_Name) Values "
		s = s & "(" & f1 & f2 & f3 & f4 & f5 & f6 & f7
		s = s & f8 & f9 & f10 & f11 & f12 & f13
		s = s & f14 & f15 & f16 & f17 & f18 & ")"
		cmd.CommandText = s
		h = cmd.ExecuteNonQuery