From on (release) to onRelease (Help needed)

Hello around:}

I need some help about action script code of a button

I’ve an old on (release) command, and i would like to go with AS2 now. But I can’t succeed in making this work out with the btn.onRelease= fonction(); command.

I’ve a [color=Blue]stylesheet [/color]([color=SeaGreen]stylesheet.css[/color]), a dynamic variable [color=Blue]pageGalleryHTML[/color] from a .txt file ([color=SeaGreen]multimedia.txt[/color]).
The content field is nammed [color=DarkOrange]TextBox[/color], Here is my current button code:

on (release) {
  var myCSS = new TextField.StyleSheet();
  var cssURL = "stylesheet.css";
  myCSS.load(cssURL);
  myloadVarsText = new LoadVars();
  myloadVarsText.load("multimedia.txt");
  myloadVarsText.onLoad = function(success) {
	 if (success) {
		 TextBox.styleSheet = myCSS;
		 TextBox.html = true;
		 TextBox.htmlText = this.pageGalleryHTML;
		} else {
			trace("not loaded");
		}
	};
}

Please help me(-: