function fnGetDomain(url) {
   return url.match(/:\/\/(.[^/]+)/)[1];
}

function onImgError(source) {
  source.style.visibility = "hidden"
  source.onerror = "";
  return true;
}

var dominio = fnGetDomain(document.location.href);
//document.images['imgCustomInetweb'].src = dominio.replace('webmail.', '') + '.gif';

document.write('<img src="/imgCustom/' + dominio.replace('webmail.', '') + '.jpg' + '" id="imgCustomInetweb" style="display:block" onerror="onImgError(this)" />');
/*
if ( dominio == 'webmail.armprevine.com.br' ) 
{
  document.location.href = 'http://webmail.sm03.inetweb.com.br';
}
*/