function focus_sub_form() {
  if (document.sub_form.email_addr.value=='yourmail@domain.com') {
      document.sub_form.email_addr.value='';
  } 
}
function blur_sub_form() {
  if (document.sub_form.email_addr.value=='') {
      document.sub_form.email_addr.value='yourmail@domain.com';
  }
}
function submitform() {
  window.open("", "formPopup", "toolbar=0,location=0,directories=0,status=0,menubar=0,scrollbars=0,resizable=0,height=200,width=500,toolbar=no", true); 
  document.sub_form.target='formPopup';
  document.sub_form.submit();
}