function button_on(button) {
  document.getElementById(button).style.background = "url(buttons/bg_blue.gif)";
}

function button_off(button) {
  document.getElementById(button).style.background = "none";
}

function review_on(layer) {
  document.getElementById(layer).style.display = "true";
}

function cursor_on(obj) {
  obj.style.cursor = 'hand';
}

function cursor_off(obj) {
  obj.style.cursor = 'default';
}

function border_on(obj) {
  obj.style.border       = '1px solid #000000';
  obj.style.borderTop    = '0';
  obj.style.borderBottom = '0';

  obj.style.paddingLeft  = '0';
  obj.style.paddingRight = '0';
}

function border_off(obj) {
  obj.style.border       = '0';
  obj.style.paddingLeft  = '1px';
  obj.style.paddingRight = '1px';
}

function show(layername) {
  layername.style.display = "";
}

function hide(layername) {
  layername.style.display = "none";
}