Arrays, fieldnames, and nesting oh my!

Thanks for even opening the post. Hopefully, you are able to help.
My problem is that I cannot successfully transfer a value from one array to another. But wait, it’s not that simple! Because I’m making a game, I’d rather not put the actual full code up. Here’s the issue:

var firstVariable = 100;
var myArray = new Array();
myArray.push({field1: "ability", field2: firstVariable});
//And so on for other variables. trace (myArray[0].field2); returns 100.
//Now create a new array
var secondArray = new Array();
secondArray[0] = myArray[0].field2;
//Here is the problem. The above (secondArray[0]) traces to undefined!

Why won’t actionscript allow me to transfer the value/variable over? Better yet, how can I fix it?