[jQuery] Looking for term in JSON

What I have currently is once the page loads the wordStats goes out
and counts the words and then it takes them and we use the most
popular to pull information from a JSON file.

The problem is that if it does not find the most popular word then it
just gives off an error and I am not sure how to provided it with a
default value.

I have pasted my code below along with a sample of my JSON.

Thanks.
<script language="javascript" type="text/javascript">
$(function() {
var count = 3;

$.extend($.wordStats.stopWords, {'retrieved': true,
'2007': true});

$.wordStats.computeTopWords(count);

for(var i = 0, j = $.wordStats.topWords.length; i < j && i
<= count; i++) {

var $type = $.wordStats.topWords[0].substring(1);

}

$.getJSON('test.json',function(data) {

$.each(data[$type], function(key,state) {

alert(state);

});
});

$.wordStats.clear();
});
</script>

//// JSON

{
'corvair' :
{ 'corvair' : 'Corvairs are fun!'},
'default' :
{'default' : 'Default Text'}
}