code: public void setOnChange(String onchange)
      {
          AbstractHtmlState tsh = getState();
          tsh.registerAttribute(AbstractHtmlState.ATTR_JAVASCRIPT, ONCHANGE, onchange);
      }
docs: Sets the onChange javascript event.
  @param onchange the onChange event.
  @jsptagref.attributedescription The onChange JavaScript event.
  @jsptagref.databindable false
  @jsptagref.attributesyntaxvalue <i>string_onChange</i>
  @netui:attribute required="false" rtexprvalue="true"
  description="Sets the onChange javascript event."