Making TextArea transparent?

if this is my code:
function xmlLoad(newXml, cssUrl) {
//formatting textfield
myText.setStyle(“background”, true);
myText.setStyle(“backgroundColor”, 0xBDC6DE);
myText.html = true;
//loading stylesheet
var xmlCss:TextField.StyleSheet = new TextField.StyleSheet();
xmlCss.onLoad = function(success) {
if (success) {
myText.styleSheet = xmlCss;
} else {
myText.text = “Stylesheet not loaded!”;
}
};

in the myText.setStyle section what codewould i nput to make it transparent?
ive tried the “_alpha”, “0” code, but that makes the imgeas and the scrollbar transparent as well.
any ideas?
Thanks