Workbook.Saved

use this property to return or set whether the latest changes in the document have been saved.

Syntax Parameters Return value
- - Boolean

SVB Example

Saving all open workbooks. 

Option Base 1
Option Explicit
Sub Main
    Dim wb As Workbook
    'Make sure that every open workbook has been saved
    For Each wb In Workbooks
        If Not(wb.Saved) Then
            wb.Save
        End If
    Next wb
End Sub