function get_element_by_id(id) {
  return document.getElementById(id);
}

function register_OnLoad_handler(func) {
  if (typeof window.addEventListener != "undefined") {
    window.addEventListener("load", func, false);
  }
  else if (typeof window.attachEvent != "undefined") {
    window.attachEvent( "onload", func );
  }
  else {
    if (window.onload != null) {
      var oldOnload = window.onload;
      window.onload = function (e) {
         oldOnload(e);
         func();
      };
    }
    else {
      window.onload = func;
    }
  }
}