_width (propriété TextField._width)

this.createTextField("my_txt", this.getNextHighestDepth(), 10, 40, 160, 120);
my_txt.background = true;
my_txt.backgroundColor = 0xFF0000;
my_txt.border = true;
my_txt.multiline = true;
my_txt.type = "input";
my_txt.wordWrap = true;

this.createTextField("width_txt", this.getNextHighestDepth(), 10, 10, 30, 20);
width_txt.border = true;
width_txt.maxChars = 3;
width_txt.type = "input";
width_txt.text = my_txt._width;
width_txt.onChanged = function() {
    my_txt._width = this.text;
}

this.createTextField("height_txt", this.getNextHighestDepth(), 70, 10, 30, 20);
height_txt.border = true;
height_txt.maxChars = 3;
height_txt.type = "input";
height_txt.text = my_txt._height;
height_txt.onChanged = function() {
    my_txt._height = this.text;
}