Во Flash 2004 MX это сделать легко, а вот в MX приходится извращаться. Примерно так:

Код:
myFormat = new TextFormat();
myFormat.align = "center";
myFormat.font = "Verdana";
myFormat.size = 14;
myFormat.color = "0x0000FF"
myFormat.underline = 0;
//===============
newFormat = new TextFormat();
newFormat.underline = 1;
newFormat.color = "0xFF0000";
//=================
this.createTextField("txt", 0,0,0,0,0);
txt.autoSize = true;
txt.selectable = 0;
txt.text = "This is the best";
txt.setTextFormat(myFormat);
this.createEmptyMovieClip("but",2);
but.createTextField("txt1", 0,0,0,0,0);
but.txt1.autoSize = true;
but.txt1.selectable = 0;
but.txt1.text = "site";
but.txt1.setTextFormat(myFormat);
this.createTextField("txt2", 4,0,0,0,0);
txt2.autoSize = true;
txt2.selectable = 0;
txt2.text = "for the flashers";
txt2.setTextFormat(myFormat);
//===========
this.onEnterFrame = function(){
txt._x = 145;
txt._y = 100;
but.txt1._x = 145+txt._width;
but.txt1._y =100;
txt2._x = 145+txt._width+but.txt1._width;
txt2._y = 100;
this.onEnterFrame = null;
}
but.onRollOver = function(){
but.txt1.setTextFormat(newFormat);
}
but.onRollOut = function(){
but.txt1.setTextFormat(myFormat);
}
but.onRelease = function(){
getURL("http://flasher.ru");
}