adding an item to a list on a different form

on form 1 i have a button called next, which takes me to form 2. i am very new to vb and not sure about some of the words you are using. would you be able to provide an example please?

on form1 i have a textbox in which i enter 'Restaurant'. I click on the Add button that i have created on form1. this button should add the word Restaurant to the listbox on form2. when i click on the 'next' button i have created on form1, i will be taken to form2. the listbox on form2 should contain the word Restaurant

this works. however, when i go back to form 1 and add another item to be added to the listbox on form2, when i go to form2 again there is nothing there

i have used the code you gave. this is what i did:

I am on form 1. I add 'Restaurant' in the textbox and click on the Add button. Then I click on the Next button so that I am taken to form 2. The word Restaurant is added to the list box. I click on the Back button so that i am taken back to form 1. I add the word 'Bank' in the textbox and click on the Add button. i click on the Next button to go to form 2 again. There is nothing in the listbox at all

Don't think the above would work.

When I go to form 2, form 1 hides so that it is not shown on the screen. when i go back to form 1, form 2 hides.

this is my code on form 2:

Imports SpeechLib
Public Class CategoryList
Dim answer

Private Sub CategoryList_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
ListBox1.Items.AddRange(items.ToArray)
End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
PointsOfInterestCategory.Show()
Me.Hide()
' sender parameter is the control that triggered
' the Click event. Convert it to a Button:
Dim btn As Button = DirectCast(sender, Button)

' Now pass the button's Text property to the
' voice.Speak method:
Dim voice As New SpVoice
voice.Speak(btn.Text, SpeechVoiceSpeakFlags.SVSFlagsAsync)

End Sub

Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged

End Sub
End Class

my first form is called PointsOfInterestCategory. this is shown in the button event on form 2 as PointsOfInterestCategory.Show()

It seems you've got my code a little jumbled. I'm not sure if you just didn't add it in correctly of if you've tried to make changes to get it to work, but it's not correct. As it is now you should be getting an error when you click button3. Also I can't tell which button is supposed to add the names to the list becuase both button3 and button1 do that. I've tried to make the appropriate fixes. Assuming I guessed correctly on which button does what this code work now.

Code for PointsOfInterestCategory form
Imports SpeechLib

Public Class PointsOfInterestCategory

Dim frm As CategoryList 'Our instance of form2
Dim items As New List(Of String) 'Internal collection of items

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)

End Sub

Private Sub PointsOfInterestCategory_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Form1.Hide()
End Sub

'This should be the button that adds items. If that's not the case
'this code should go in that button.
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

Dim newItem As String = TextBox1.Text
items.Add(newItem) 'Add new item to our list

'If Form2 exists then add the item to it's listbox
If frm IsNot Nothing AndAlso Not frm.IsDisposed Then frm.ListBox1.Items.Add(newItem)

' sender parameter is the control that triggered
' the Click event. Convert it to a Button:
Dim btn As Button = DirectCast(sender, Button)

' Now pass the button's Text property to the
' voice.Speak method:
Dim voice As New SpVoice
voice.Speak(btn.Text, SpeechVoiceSpeakFlags.SVSFlagsAsync)
End Sub

Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
Form1.Show()
Me.Hide()
' sender parameter is the control that triggered
' the Click event. Convert it to a Button:
Dim btn As Button = DirectCast(sender, Button)

' Now pass the button's Text property to the
' voice.Speak method:
Dim voice As New SpVoice
voice.Speak(btn.Text, SpeechVoiceSpeakFlags.SVSFlagsAsync)

End Sub

Private Sub Label3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)

End Sub

'This looks like it should be the button that shows the other form
'The only changes I made were in this method.
Private Sub Button3_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click

Me.Hide()

If frm Is Nothing OrElse frm.IsDisposed Then
frm = New CategoryList
frm.ListBox1.Items.AddRange(items.ToArray)
frm.Show()
Else
frm.Visible = True
End If

'' sender parameter is the control that triggered
'' the Click event. Convert it to a Button:
Dim btn As Button = DirectCast(sender, Button)

'' Now pass the button's Text property to the
'' voice.Speak method:
Dim voice As New SpVoice
voice.Speak(btn.Text, SpeechVoiceSpeakFlags.SVSFlagsAsync)

End Sub
End Class

Code for CatagoryList form
Imports SpeechLib
Public Class CategoryList
Dim answer

Private Sub CategoryList_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'The next line isn't necessary anymore
'You should remove this code.
'ListBox1.Items.AddRange(items.ToArray)
End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
PointsOfInterestCategory.Show()
Me.Hide()
'' sender parameter is the control that triggered
'' the Click event. Convert it to a Button:
Dim btn As Button = DirectCast(sender, Button)

'' Now pass the button's Text property to the
'' voice.Speak method:
Dim voice As New SpVoice
voice.Speak(btn.Text, SpeechVoiceSpeakFlags.SVSFlagsAsync)

End Sub

Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged

End Sub
End Class