Excel Macro for deleting rows IF cells not...

Option Explicit
'InterlinearDeletion by Piotr Kuchno 08.01.2010
'This macro lets you delete a row that do not contain a specific string

Dim strToKeep       As String  'string that let us keep a row that contains it
Dim strToCompare    As String  'string taken from a cell(x, y)
Dim rngSrc          As Range   'field size to operate, search and delete
Dim numRows         As Long    'total number of selected rows to operate, search and delete
Dim selCol          As Long    'sel[ected] column
Dim selRow          As Long    'sel[ected] row
Dim compOut         As Integer 'com[pare] out - returns 0 in case of no match or >0 if there is a match
Dim actRow          As Long    'act[ual] row - used temporary in For/Next loop
Dim J               As Long    'for For/Next loop
Dim sheetName       As String  'keeps sheet's name (different languages have it under different name)
Dim DeletedRows     As Long    'just for an information how much rows were deleted

Private Sub cmdStart_Click()
    Call InterlinearOperation
End Sub

Private Sub InterlinearOperation()

    strToKeep = InputBox("Write a (part of) string you want to keep as a whole row:", "Keep Rows")
    If strToKeep = "" Then Exit Sub 'nothing to compare so... exit
    'strToKeep = "your string" 'you may use it instead of InputBox window
    Set rngSrc = ActiveSheet.Range(ActiveWindow.Selection.Address) 'sets the field size

    numRows = rngSrc.Rows.Count 'total number of selected rows
    selCol = rngSrc.Column      'selected column
    selRow = rngSrc.Row         'selected row
    
    sheetName = ActiveSheet.Name 'reads active sheet's name
    
    DeletedRows = 0 'have to start from the scratch
        
    actRow = selRow 'actRow will change so we need to leave 'selRow' intact
    
    For J = selRow To numRows
        strToCompare = Worksheets(sheetName).Cells(actRow, selCol) 'reads a string from cell(x, y)
        compOut = InStr(1, strToCompare, strToKeep, vbTextCompare) 'makes comparison and gives its result
        If strToCompare = "" Then compOut = 1 'cell(x, y) is empty so lets fool it to not deleting
        If compOut = 0 Then                           'not found the string we are looking for so...
            Worksheets(sheetName).Rows(actRow).Select '...selects actual row,...
            Selection.Delete Shift:=xlUp              '...deletes it and shifts all rows up
            actRow = actRow - 1 'we have one row less so we need to mark this for strToCompare
            DeletedRows = DeletedRows + 1 'counts deleted rows
        End If
        actRow = actRow + 1 'comparison is done so we need to increase this array to give the correct number to strToCompare
    Next J
    
    MsgBox "Number of deleted rows: " & DeletedRows

End Sub