How do I get my history function working on my tabbed browser?

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Visual-Studio

WebBrowserControl

I am attempting to create a history function for my tabbed web browser, however, I have two errors:

1. 'item' is not delcrared

2. navigate is not a member of TabControl

Here is the code. The code in bold are the problematic areas:

Public Class history
    Private Sub history_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        lbHistory.Items.Add(item)
    End Sub
    Private Sub btnClearHistory_Click(sender As Object, e As EventArgs) Handles btnClearHistory.Click
        My.Settings.history.Clear()
        lbHistory.Items.Clear()
    End Sub
    Private Sub btnRemoveHistory_Click(sender As Object, e As EventArgs) Handles btnRemoveHistory.Click
        My.Settings.history.Remove(lbHistory.SelectedItem)
    End Sub

    Private Sub btnLoadHistory_Click(sender As Object, e As EventArgs) Handles btnLoadHistory.Click
        main.TabControl1.navigate(lbHistory.SelectedItem)
    End Sub
    
End Class

What I have tried:

I have done research on my own using Google and followed some code suggestions, but to no avail.