TLF multiline no wrap and text height problem

When I set flow behaviour on "multiline no wrap" then I can't change height

for example put 2 TLF text field on scene - one with behaviour on "multiline" - second "multiline now wrap"

try this code

stage.addEventListener(MouseEvent.CLICK, resizeField);

var _height:int = 200;

txt1.wordWrap = true;

txt1.multiline = true;

txt1.border = true;

txt1.autoSize = TextFieldAutoSize.LEFT;

txt2.wordWrap = true;

txt2.multiline = true;

txt2.border = true;

txt2.autoSize = TextFieldAutoSize.LEFT;

function resizeField(e:MouseEvent):void

{

    _height = _height+100;

    txt1.height = _height;

    txt2.height = _height;

}

field with behaviour on "multiline" is resizing down

field with behaviour on "multiline now wrap" is not working - still have this same height - how can I change this dynamic in as code?