I am hoping a second set of eyes can help me find my error. I am creating a basic JSON object and trying to display the values in the JSON object. Field 1 displays properly, but fields 2 & 3 display as undefined. Can anyone see what my problem is?

Thanks in advance for your time.

Code:
<html>
<head>
    <title>String to JSON in JavaScript</title>
    <script type="text/javascript">

	var mockJSON = 
{
	"testing" :
	[
		{ "field1" : "field1" },
		{ "field2" : "field2" },
		{ "field3" : "field3" }
	]
};
	
	function createJSON() {
		alert( "field1: " + mockJSON.testing[0].field1 );
		alert( "field2: " + mockJSON.testing[0].field2 );
		alert( "field3: " + mockJSON.testing[0].field3 );
	}
	
    </script>
</head>
<body onLoad="">
	<a href="javascript:createJSON();">Build JSON</a>
</body>
</html>