macro error code

keep getting error code in macro, on line copy invoice to new workbook 

sorry new to this ,any help appreciated

Sub saveinvwithnewname()
Dim Newfn As Variant
copy invoice to a new workbook
Active Worksheet.Copy
Newfn = "c:/users/steves desktop/inv" & Range("b7").Value & ".xlsx"
Activeworbook.saveas Newfn, Fileformat = xmlopenworkbook
Active Workbook.Close
nextinvoice
End Sub