Substrings

Este programa teria que retornar as seguintes substrings e apresenta-las no formulário nos Lab 2: First five characters are "This "

Lab 3: Last five characters are 'test '

Label4 : Five characters in the middle are 'is is'

Porém os códigos em vermelhos estão dando erros alguém sabe como corrigir ?

Private Sub Command1_Click()

Dim string1 As String

Dim String2 As String

Dim String3 As String

Dim string4 As String

string1 = Text1.Text

String2 = Left(string1, 5)

String3 = Right(string1, 5)

string4 = Mid(string1, 3, 5)

Label2.Caption = "First five characters are "& _ " ' " &

string2 & " ' "

Label3.Caption = "Last five characters are "&_"'"&

string3 & " ' "

Label4.Caption = "five characters in the middle are " &_ " '

" & string4 & " ' "

End Sub