Repeating a cell value in Excel

This is a request I have had a number of times.. In excel you want to copy the value of the cell above your current position if your current position is blank

To start this macro click on a row 2 or lower with a value in the cell above, change the value of x in the macro to the number of lines you want ot repeat

Sub Macro1()
'
' change the value of x to the number of lines to fill
Dim I, x
x=1500
Do While I < x
    If ActiveCell.Value = "" Then
        ActiveCell.Offset(-1, 0).Select
        Selection.Copy
        ActiveCell.Offset(1, 0).Select
        ActiveSheet.Paste
    End If
    ActiveCell.Offset(1, 0).Select
    I = I + 1
Loop
End Sub