Run Macro only if Column is Blank

Hi,

I have data in Column P & Column Q. Unless I clear the data in that cell by removing manually, I do not want macro to proceed further.

E.g.
1) If there is a value in Cell P & Q, and if I run macro. I need a popup msg that "Complete the manual checking"
2) If there is no value in Cell P & Q, then I only I should be allowed to execute my next macro which is

Application.ScreenUpdating = False
Sheets("Dump").Activate
Sheets("Dump").Range("R6").Select
Do Until ActiveCell.Value = ""
    For Each Cell In Sheets("All Earnings").Range("C2:C" & Sheets("All Earnings").UsedRange.Rows.Count + 1)
        If Cell.Value = ActiveCell.Value And Cell.Offset(, 4).Value = "Yes" Then
        Sheets("Data for Move").Range("A" & Rows.Count).End(3)(2) = " "
        ActiveCell.EntireRow.Copy Sheets("Data for Move").Range("A" & Rows.Count).End(3)(2)
        End If
    Next Cell
    Sheets("Dump").Activate
    ActiveCell.Offset(1).Select
Loop
Application.ScreenUpdating = True

Please assist.

Thanks