title: looping through an unknown range of rows in excel
body: <p>say i have 5 columns and god knows how many row. All the cells in this range are populated except for a few cells in the last column.
  i need to loop through all the rows (starting in A1) until i get to the last row, and for each row that has a cell populated in the last column, display a message box saying "hello"</p>
  
  <p>I'm just really unsure how to start the loop.
  I've tried googling, but I dont understand. I know how i'd check for empty cells, and how to diply the message box, but not how to find the end of the range.</p>