How can I add javascripts to iTextsharp created textfields?

To add an onMouseOver JavaScript action to a TextField, use following code:

TextField field = new iTextSharp.text.pdf.TextField(writer,
    new iTextSharp.text.Rectangle(x, y - h, x + w, y), name);
field.BackgroundColor =
    new BaseColor(bgcolor[0], bgcolor[1], bgcolor[2]);
field.BorderColor =
    new BaseColor(bordercolor[0], bordercolor[1], bordercolor[2]);
field.BorderWidth = border;
field.BorderStyle = PdfBorderDictionary.STYLE_SOLID;
field.Text = text;
// PROBLEM:
// field.AddJavaScript = PdfAction.JavaScript(
// "this.getField(\"Total_0\"").value = ( this.getField(\""Quantity_0\"").value