Mouse over action - play label in symbol

I have a symbol on the stage named “final”. Inside “final” I have a symbol named “imagetiles” and in that a symbol named “webdrop” and an image named “website”. I want to add a mouse over action to the image “website” that will play a label in the “webdrop” symbol. Below is the code I’m using. It works fine when I initiate the call from a trigger in the timeline of “imagetiles” but when I put it in the mouse over action for the image “website” it doesn’t work. What am I doing wrong here? Thanks in advance for any assistance.

Code;

sym.$("webdrop").show();

sym.getSymbol("webdrop").play("open");

Symbol hierarchy;

Stage

-final (symbol)

--imagetiles (symbol)

---website image (mouse over action for “webdrop”)

---webdrop (symbol with labels “open” and “close”)