Private Sub displayTask(task As Task, modifiable As Boolean)
        'add a border to the displayed task in the list of tasks
        CType(task.controls(0), Panel).BorderStyle = BorderStyle.FixedSingle
        'remove the controls that are already contained in the display area
        grpTask.Controls.Clear()
        'index allowing to compute the vertical position of the controls
        Dim indexY = 0
        'creation of a Panel in which to add the controls
        Dim pnlTask As New Panel
        pnlTask.AutoSize = True
        pnlTask.Anchor = AnchorStyles.Left & AnchorStyles.Bottom & AnchorStyles.Right & AnchorStyles.Top

        If Not modifiable Then
            'WRITE HERE THE CODE FOR CREATING THE CONTROLS NEEDED FOR DISPLAYING A TASK THAT CANNOT BE MODIFIED
            '=> LABELS
            Dim lblTitle As New Label
            Dim lblDescription As New Label
            Dim lblCategory As New Label
            Dim lblDeadline As New Label

            Dim cat As String

            Select Case task.category
                Case Category.family
                    cat = "family"
                Case Category.home
                    cat = "home"
                Case Category.home
                    cat = "homework"
                Case Category.leisure
                    cat = "leisure"
                Case Else
                    cat = "homework"
            End Select

            'Initializing lblTitle
            lblTitle.Text = "Title : " + task.title
            lblTitle.MaximumSize = New Size(190, 0)
            lblTitle.AutoSize = True
            lblTitle.Location = New Point(10, 0)

            'Initializing lblDescription
            lblDescription.Text = "Description : " + task.description
            lblDescription.AutoSize = True
            lblDescription.MaximumSize = New Size(190, 100)
            lblDescription.Location = New Point(10, 15)

            'Initializing lblCategory
            lblCategory.Text = "Category : " + cat
            lblCategory.AutoSize = True
            lblCategory.Location = New Point(10, 120)

            'Initializing lblDeadline
            lblDeadline.Text = "Deadline : " + task.deadline.Day.ToString + "/" + task.deadline.Month.ToString + "/" + task.deadline.Year.ToString
            lblDeadline.AutoSize = True
            lblDeadline.Location = New Point(10, 135)

            With pnlTask
                .Controls.Add(lblTitle)
                .Controls.Add(lblDescription)
                .Controls.Add(lblCategory)
                .Controls.Add(lblDeadline)
            End With
        Else
            'WRITE HERE THE CODE FOR CREATING THE CONTROLS NEEDED FOR DISPLAYING A TASK THAT CAN BE MODIFIED
            '=> TEXTBOX, COMBOBOX, CHECKBOX AD  DATETIMEPICKER
            '=> OK AND CANCEL BUTTONS
            'references to controls that will be used to modify a task
            txtModifTitle = New TextBox
            txtModifDescr = New TextBox
            cboModifCat = New ComboBox
            chkModifDate = New CheckBox
            dateModif = New DateTimePicker
            Dim btnOk As New Button
            Dim btnCancel As New Button

            'Initializing txtModifTitle
            txtModifTitle.Text = task.title
            txtModifTitle.Width = 150

            'Initializing txtModifDescr
            With txtModifDescr
                .Text = task.description
                .Height = 90
                .Width = 190
                .Multiline = True
                .Top = txtModifTitle.Top + txtModifTitle.Height + 5
            End With

            'Initializing cboModifCat
            cboModifCat.Top = txtModifDescr.Top + txtModifDescr.Height + 5
            Dim cats As Array
            cats = System.Enum.GetValues(GetType(Category))
            For Each cat In cats
                cboModifCat.Items.Add(cat)
            Next
            cboModifCat.SelectedIndex = task.category


            'Initializing chkModifDate
            chkModifDate.Text = "Deadline"
            chkModifDate.Top = cboModifCat.Top + cboModifCat.Height + 5

            'Initializing dateModif
            dateModif.Top = chkModifDate.Top + chkModifDate.Height + 5
            dateModif.Width = 180

            'Initializing btnOk
            btnOk.Text = "Ok"
            btnOk.Top = dateModif.Top + dateModif.Height + 5
            AddHandler btnOk.Click, AddressOf clickOk

            'Initializing btnCancel
            btnCancel.Text = "Cancel"
            btnCancel.Top = btnOk.Top
            btnCancel.Left = btnOk.Left + btnOk.Width + 5
            AddHandler btnCancel.Click, AddressOf clickCancel

            With pnlTask
                .Controls.Add(txtModifTitle)
                .Controls.Add(txtModifDescr)
                .Controls.Add(cboModifCat)
                .Controls.Add(chkModifDate)
                .Controls.Add(dateModif)
                .Controls.Add(btnOk)
                .Controls.Add(btnCancel)
            End With

        End If
            'add the panel containing the controls to the display area.
            pnlTask.Location = New Point(5, 20)
        grpTask.Controls.Add(pnlTask)
    End Sub