You defined your attachPolygonInfoWindow function with 4 argument, but only provide one when you call it:
// definition
function attachPolygonInfoWindow(polygon, html, event, expires)
...
// call
attachPolygonInfoWindow(eventWarnings);
Probably you want (I don't see the html or expires parameters being used):
attachPolygonInfoWindow(eventWarnings, "", event, null);
The other option would be to change the definition to:
// definition
function attachPolygonInfoWindow(polygon, event, expires)
and the call to (assuming you are going to use "expires" for something):
attachPolygonInfoWindow(eventWarnings, event, expires);
As it doesn't look like you need to pass in that parameter (event is serving the function that I would expect it to serve).
Also, FYI, you have a "hanging comma" in your alertColors.js which make IE unhappy...