function trysubmit() {

  var field = document.getElementById( 'myemail' );
  if( field == null ) document.sendtouser.submit();

  if( field.value == '' || field.value == undefined ) {

    var warning = document.getElementById( 'myemailwarning' );
    if( warning == null ) document.sendtouser.submit();

    warning.style.display = '';
    return;
  }

  document.sendtouser.submit()
}