Vertical Lines - Area Chart

I'm trying to create an area chart to show the change in the number of staff working in my store over time. Unfortunately, Excel likes to draw diagonal lines. That is if I have the following data:

9:00AM - 1 staff
10:00AM - 2 staff
11:00AM - 1 staff

Excel will draw a diagonal line between each data point, rather than creating a box. This gives the illusion that there are somehow half people working at 9:30 and 10:30. Is there a workaround?

Thanks for posting back and sharing your solution.

Using the column chart is probably the simplest solution but for reference here is information on creating a step chart.
http://www.andypope.info/charts/stepchart.htm