CheckBox Data to ListBox (VBNet) - vb.net

Question

the problem with my code is that when i initially select a particular checkbox it works well and displays selected item in listbox, but when selected again it creates another entry within the listbox and when i remove it i have to uncheck the same checkbox the times it has been displayed in the listbox when i click the btnSubmit.
Can someone tell me what's wrong with the code, thank you so much
Private Sub btnSubmit_Click(sender As Object, e As EventArgs) Handles btnSubmit.Click
If CheckBox1.Checked Then
ListBox1.Items.Add(CheckBox1.Text)
Else
ListBox1.Items.Remove(CheckBox1.Text)
End If
If CheckBox2.Checked Then
ListBox1.Items.Add(CheckBox2.Text)
Else
ListBox1.Items.Remove(CheckBox2.Text)
End If
If CheckBox3.Checked Then
ListBox1.Items.Add(CheckBox3.Text)
Else
ListBox1.Items.Remove(CheckBox3.Text)
End If
If CheckBox4.Checked Then
ListBox1.Items.Add(CheckBox4.Text)
Else
ListBox1.Items.Remove(CheckBox4.Text)
End If
If CheckBox5.Checked Then
ListBox1.Items.Add(CheckBox5.Text)
Else
ListBox1.Items.Remove(CheckBox5.Text)
End If
If CheckBox6.Checked Then
ListBox1.Items.Add(CheckBox6.Text)
Else
ListBox1.Items.Remove(CheckBox6.Text)
End If
End Sub

Answer 1

You can do it like this:
Private Sub btnSubmit_Click(sender As Object, e As EventArgs) Handles btnSubmit.Click
ListBox1.Items.Clear
CheckObj(CheckBox1)
CheckObj(CheckBox2)
CheckObj(CheckBox3)
CheckObj(CheckBox4)
CheckObj(CheckBox5)
CheckObj(CheckBox6)
End Sub
Sub CheckObj (obj as Checkbox)
if obj.checked then ListBox1.Items.Add (obj.text)
End Sub