Capitalize first character & spacing - Excel

[VBFnewcomer]

Dim prev As Range   ' range to leave
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
On Error Resume Next
If Not prev Is Nothing Then
    If prev.Column = 1 Then  ' column A
        pos = InStr(prev.Value, ".")
        If pos > 0 Then   ' period in cell
            myarr = Split(prev.Value, ".")  ' divide sentences into arrray
            For i = 0 To UBound(myarr)
                myarr(i) = Trim(myarr(i))
                If Len(myarr(i)) > 0 Then myarr(i) = UCase(Left(myarr(i), 1)) & Mid(myarr(i), 2)
            Next
            prev.Value = Join(myarr, ". ")
        End If
    End If
End If
Set prev = Target 'set range for next cell to leave
End Sub

this code is not working the extra spaces remain as it was....
Edit: The code works after I remove On Error Resume Next.