Textfield.StyleSheet not working (CSS)

programming flash
1

The tutorials for using CSS in Flash seem pretty straightforward, but for some reason they just don’t work for me. I’m using this code:


this.createTextField("myText", 1, 100, 100, 300, 100);
myText.multiline = true;
myText.wordWrap = true;
myText.html = true;
var myFormat:TextField.StyleSheet = new Textfield.StyleSheet();
myFormat.onLoad = function(success) {
    trace("yay");
    if(success) {
        myText.styleSheet = myFormat;
        myText.htmlText = "<p class='big'>Yes!</p><p class='small'>It works.</p>";
    } else {
        myText.htmlText = "Aw.";
    }
}
myFormat.load("default.css");

This is my CSS file:


.big, .small {
        color: #000000;
        }
.big    {
        font-size: 16px;
        }
.small    {
        font-size: 10px;
        }

When I Debug>Variables, there is one line in particular that seems to be the key:

Variable _level0.myFormat = undefined

Any ideas? I’m sure the answer must be simple, but I just can’t see it.