Configuring Pop-Up Box

AdamHufnagel

I am creating a webGIS that displays transit stops and routes using ArcGIS Online. I have created the layers in ArcGIS Desktop and imported shapefiles. When creating the stop nodes shapefile, I included all stops on all routes inside one shapefile. This means I have stops that some routes do not stop at; as such there is a NULL value in the Time of Stop field for these routes. If this is confusing let me know.
After creating the map and doing some configuring, I have the settings so Time of Stop is displayed, however when I click on the stop I see ALL stops. And as such, if the value is NULL then whitespace is displayed...this is what I would like to get rid of (save the user from scrolling or being confused by the lack of display). It is NOT possible using the field selector, as each stop is different from the next.
I feel this may be possible using the RichText option in Explorer, however I haven't made a break through.

AdamHufnagel

Create stop layer using Online's tools and it is displayed appropriately.