If( currentID = LBound(articles) ) Then
Dim previous as String = 'Previous'
Dim next as String = '<a href="yourpage.aspx?id=1">Next</a>'
Else
If ( currentID = UBound(articles) ) Then
Dim previous as String = '<a href="yourpage.aspx?id=' & (UBound(articles)-2) & '">Previous</a>'
Dim next as String = 'Next'
Else
Dim previous as String = '<a href="yourpage.aspx?id=' & (currentID-2) & '">Previous</a>'
Dim next as String = '<a href="yourpage.aspx?id=' & (currentID) & '">Next</a>'
End If
End If