Assign Different Style To Lines In A Line Chart

I am creating a simple line chart using SSRS 2005. The chart will display date vs. cumulative enrollment. In the line chart I want to display two lines. One line represents expected enrollment data and the other represents actual enrollment data. I would like the expected data line to be a dashed line and the actual line to be a solid line. I have a single dataset that contains data for both lines. I have added a column to the dataset that acts as a flag to indicate whether the data point is expected or actual. I have dropped the enrollment field from my dataset into "Drop data fields here". I have dropped the date field from my dataset into "Drop category fields here". I have dropped the flag field from my dataset into "Drop series fields here".

When I change the style of the series it changes the styles of both lines. How can assign a different line style to each line? Is this even possible with the way I have set up the chart? Is there another way to set up the chart to accomplish what I am trying to do?