Need Help on an ADX indicator...

When the "-DI" crosses the "ADX" from top to bottom, a buy arrow should appear. When it crosses from bottom to top, a buy arrow should appear.
Likewise, when the "+DI" crosses the ADX from bottom to top, a buy arrow should appear, and when it crosses from top to bottom, a sell arrow should appear.

I placed an arrow in the image below where the intersection that occurs should receive the arrow.