//****************************
 function VerSiEmailOk(validacion) 
//****************************
{
    var puntoanterior = false;
    var PuntoTrasArroba = false;
    var Arrobaencontrada = false;
	var Error = false;

  _sEmail = validacion.value;
  if(_sEmail.length == 0) {
    alert("You must fill in email search row");
	validacion.focus();
	return false;
  }

  for (var _i=0; _i<_sEmail.length; _i++) {
    var _ch = _sEmail.charAt(_i).toLowerCase();
    if (_ch == "@") { // LEEMOS LA @
      if((_i == 0) || (_i==(_sEmail.length - 1))){
        alert("@ inaccurate placed");
		validacion.focus();
		return false;
      }
      if(Arrobaencontrada){
        alert("Only is allowed one @ in one e-mail address");
        validacion.focus();
		return false;
      }else {
        Arrobaencontrada=true;
		if (puntoanterior){
		  alert("The first part of email cannot finish with a dot");
		  puntoanterior = false;
		  validacion.focus();
	      return false;
		}
      }
    }else { //LEEMOS ALGO DIFERENTE DE @
				
	  // EL PRIMER CARACTER HA DE SER LETRA (?)
      if (_i==0 && (_ch < 'a' || _ch > 'z') && (_ch != '_')){
        alert("The first symbol of email must be a proper letter or '_'");
	    puntoanterior = false;
	    validacion.focus();
	    return false;
	  }else{
	  if (_ch=='.'){ // SI SE ENCUENTRA UN PUNTO
	    if (Arrobaencontrada) PuntoTrasArroba = true;
	    if (puntoanterior){
          alert("The e-mail cannot include two dots together");
	      validacion.focus();
	      return false;
	    }
	    puntoanterior = true;
	  }else { // MIRAMOS QUE SEA LETRA, NUMERO O '_'
	  if ((_ch < 'a' || _ch > 'z') && (_ch < '0' || _ch > '9') && (_ch != '_') && (_ch != '-')){
        alert("The e-mail must be made up only with proper letter and/or numbers and/or '_' and/or '-'");
	    puntoanterior = false;
	    validacion.focus();
	    return false;
	  }else{
	    puntoanterior = false;
	  }}}
	  
	}//ELSE @
  }// FOR

  if(!Arrobaencontrada){
    alert("You must include @ symbol in the E-mail address");
    validacion.focus();
    return false;
  }
  if(puntoanterior){
    alert("The e-mail cannot finish with a dot '.'");
    validacion.focus();
    return false;
  }
  if(!PuntoTrasArroba){
    alert("Inaccurate e-mail address (dot symbol '.' is necessary after @");
    validacion.focus();
    return false;
  }
    return true;
}