Summing duplicates

Many thanks Mark this does the trick. I do have another somewhat linked question. I have data going down 100 rows and about 20 columns across. However i need to delete some based on a condition. The condition is that if certain words are in column C i want the row to be deleted and in addition if column D is blank then the row should also be deleted. I wrote the below for the first part to remove based on words but that doesnt seem to be working:

ub Delete_Based_on_Criteria()


Dim X As Long
Dim Z As Long
Dim LastRow As Long
Dim FoundRowToDelete As Boolean
Dim OriginalCalculationMode As Long
Dim RowsToDelete As Range
Dim SearchItems() As String
Dim DataStartRow As Long
Dim SearchColumn As String
Dim SheetName As String


DataStartRow = 9
SearchColumn = "C"
SheetName = "Book1"


SearchItems = Split("FORWARD, SPOT, private eqty")


On Error GoTo Whoops
OriginalCalculationMode = Application.Calculation
Application.Calculation = xlCalculationManual
Application.ScreenUpdating = False

With Worksheets(Book1)
LastRow = .Cells(.Rows.Count, SearchColumn).End(xlUp).Row
For X = LastRow To DataStartRow Step -1
FoundRowToDelete = False
For Z = 0 To UBound(SearchItems)
If InStr(.Cells(X, SearchColumn).Value, SearchItems(Z)) Then
FoundRowToDelete = True
Exit For
End If

Next

If FoundRowToDelete Then
If RowsToDelete Is Nothing Then
Set RowsToDelete = .Cells(X, SearchColumn)
Else
Set RowsToDelete = Union(RowsToDelete, .Cells(X, SearchColumn))
End If

If RowsToDelete.Areas.Count > 100 Then
RowsToDelete.EntireRow.Delete
Set RowsToDelete = Nothing
End If
End If

Next

End With
If Not RowsToDelete Is Nothing Then
RowsToDelete.EntireRow.Delete
End If

Whoops:
Application.Calculation = OriginalCalculationMode
Application.ScreenUpdating = True



End Sub