Windows 7: Excel Line Chart

I am trying to do a simple line chart using Excel in Office 2007.
I have the dates in weekly order and two columns of prices, I want the chart to show the change in prices each week.
I select these three columns then go to Insert and select the first line chart shown.
It displays the price changes and the date format but by the month not the week.
In there anyway to get this data displayed weekly?

Thanks
jack

Just highlight the time axis, then right-click and go to Format Axis...

In the dialogue box, change Major unit: from Auto to Fixed, and set it to 7 days (see screenshot). That will give you a weekly chart

Thanks very much.

jack