I am trying to work through the online training provided by Microsoft about
Excel 2003 and I have run into an issue with the Macro lesson.

Following the instructions exactly, I have entered this macro in to a module
in the spreadsheet:

Sub CountRows()

x = ActiveCell.Row
y = ActiveCell.Column
z = 0

Do While Cells(x, y).Value < ""
x = x + 1
z = z + 1
Loop

MsgBox "There are " & z & " rows in the current range."

End Sub

When I try to run the macro, it tell me that variable x is undefined. I
tried going into the spreadsheet and placing the focus where they said and
running it from there, but I get the same message.

Please help me understand what I need to do to fix this. I am doing the
training so that I can understand this, but if the training is wrong, how am
I supposed to learn?

Feel free to talk to me like a child, I'm completely new to VBA.

Thank you to all who offer help.