Private Sub btnCIInsert_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCIInsert.Click
        If txtCIStudNo.Text = "" Or txtCILname.Text = "" Or txtCIFname.Text = "" Then
            MsgBox("Please fill in the required fields.", MsgBoxStyle.Exclamation)

            'focus on the correct field
            If txtCIStudNo.Text = "" Then
                txtCIStudNo.Focus()
            ElseIf txtCIFname.Text = "" Then
                txtCIFname.Focus()
            ElseIf txtCILname.Text = "" Then
                txtCILname.Focus()
            End If
        Else
            Dim msg As MsgBoxResult = MsgBox("Are you sure you want to save?", MsgBoxStyle.YesNo) 'Prompt for saving
            'Check user choice
            If msg = MsgBoxResult.Yes Then ' If Yes
                'Check for valid student number
                If txtCIStudNo.TextLength = 7 Then
                    Dim dteSession As String = dtpCIInsert.Value.Date
                    Dim strLname As String = StrConv(txtCILname.Text, VbStrConv.ProperCase)
                    Dim strFname As String = StrConv(txtCIFname.Text, VbStrConv.ProperCase)
                    Dim intStudNo As Integer = Convert.ToInt32(txtCIStudNo.Text)

                    'Execute SQL statements
                    Dim connCIcmd As New SqlCommand("SELECT Stud_Number FROM Student_Information WHERE Stud_Number = " _
                                                    & intStudNo, connMain.Conn)
                    Dim connCIdr As SqlDataReader = connCIcmd.ExecuteReader

                    'Check if student has record
                    If connCIdr.HasRows = 0 Then
                        MsgBox("The student doesn't exist in the database.", MsgBoxStyle.Exclamation)
                    Else
                        connCIcmd.CommandText = "SELECT Stud_Number, Coun_Date FROM Counseling WHERE Stud_Number = " _
                                                & intStudNo & " AND Coun_Date = '" & dteSession & "'"
                        connCIdr.Close()
                        Dim connCIdr2 As SqlDataReader = connCIcmd.ExecuteReader
                        If connCIdr2.HasRows = 0 Then
                            'Change SQL statement
                            connCIcmd.CommandText = "INSERT INTO Counseling(Coun_Lname, Coun_Fname, Coun_Date, Stud_Number)" _
                                                    & "VALUES('" & strLname & "','" & strFname & "','" & dteSession & "'," _
                                                    & intStudNo & ")"
                            connCIdr2.Close() 'Close reader
                            connCIcmd.ExecuteNonQuery()

                            MsgBox("The database has been updated.", MsgBoxStyle.Information)

                            calCSCalendar.Dates.Clear()
                            calCSCalendar_Populate()

                            'reset fields
                            txtCIStudNo.Text = ""
                            txtCILname.Text = ""
                            txtCIFname.Text = ""
                            txtCIStudNo.Focus()
                        Else
                            MsgBox("The counseling information already exist.", MsgBoxStyle.Exclamation)
                        End If
                    End If
                Else
                    MsgBox("Invalid student number. Please try again.", MsgBoxStyle.Exclamation) 'Displat error msg

                    'Reset txtPIStudNo
                    txtCIStudNo.Text = ""
                    txtCIStudNo.Focus()
                End If
            ElseIf msg = MsgBoxResult.No Then 'If No
                txtCIStudNo.Focus() 'set focus to txtPIStudNo
            End If
        End If
    End Sub