Cross Tab Query (blank value show X)

I have a query that shows employee attendance. I created a cross tab query for this. The cross tab query shows the names of employees on the rows and the dates as the column headings. In the columns it show Present if atx_time_amount >0 and X if it is < 0. Only thing I realized is the atx_time_amount field will never be a negative number. It will always have a positive number or be blank if they are absent. So I am trying to figure out how to make it so the report shows present for atx_time_amount > 0 and X for a blank field. I added an attachment so you can see what I am working with.

THANKS!
Query.PNG