Macro debugging

Hi, I have the following code which returns a 'Subscript out of range' error when I run it. I have a function with input in cell F2 and output in cell N2. I'd like to take a list of non-null values in column C as inputs and record the corresponding outputs in column D.

Sub Calculate_Matches()
    Dim i As Integer
    i = 3

    Do While Worksheets("All_Data").Cells(i, 6) <> ""
        If Worksheets("All_Data").Cells(i, 3) <> "" Then
            Worksheets("All_Data").Cells(2, 6).Value = Worksheets("All_Data").Cells(i, 3).Value
            Worksheets("All_Data").Cells(i, 4).Value = Worksheets("All_Data").Cells(2, 14).Value
        i = i + 1
    End If
Loop
End Sub

I'm new to VBA - Could someone please tell me what the problem is?
Many thanks!

I think your sheetname is without a underscore.
Worksheets("All Data")

Sub Calculate_Matches()
    Dim i As Integer
    i = 3
With Sheets("All Data")
    Do While .Cells(i, 6) <> ""
        If .Cells(i, 3) <> "" Then
           .Cells(2, 6).Value = .Cells(i, 3).Value
           .Cells(i, 4).Value = .Cells(2, 14).Value
        i = i + 1
    End If
  Loop
 End With
End Sub

See http://www.cpearson.com/excel/DebuggingVBA.aspx

What happens when you step through it?

You're welcome.

Nothing will improve your code-writing skills like debugging your own code.