one possibility: you could have all your texts in an array. then all your buttons have a var called "itemNum" that goes from 0 to x and corresponds with the text in the array. you then fill the text field in your scroller with the respective text.
Actionscript Code:
_root.allTexts = ["text1", "text2", "text3"];
button01.itemNum = 0;
button02.itemNum = 1;
button03.itemNum = 2;
button01.onRelease = function(){
// put all you stuff here, plus:
_root.scroller.yourTextFieldName.text = _root.allTexts[this.itemNum];
}