function validRequired(formField,fieldLabel,type){
  var result = true;
  var regSTR = new RegExp("[^0-9]*$", "i");
  var regNUM = new RegExp("^[a-zA-Z0-9]", "i");
  var regEML = new RegExp("^[a-zA-Z0-9\._-]+@[a-zA-Z0-9\-]+\.[a-zA-Z\.]{2,3}$", "g");
  if (formField.value == ""){
    alert('Por favor complete el campo "' + fieldLabel + '".');
    formField.focus();
    result = false;
  }else{
  	switch(type){
  		case 'str':
  		    if (!formField.value.search(regSTR)){
  		    	result = true;
  		    }else{
  		        alert('Por favor complete el campo "' + fieldLabel + '" correctamente.');
  		        formField.value = '';
  		        formField.focus();
                result = false;
  		    }
  		break;
  		
  		case 'strnum':
  		    if (!formField.value.search(regNUM)){
  		    	result = true;
  		    }else{
  		        alert('Por favor complete el campo "' + fieldLabel + '" solo con números o letras.');
  		        formField.value = '';
  		        formField.focus();
                result = false;
  		    }
  		break;
  		
  		case 'eml':
  		    if (!formField.value.search(regEML)){
  		    	result = true;
  		    }else{
  		        alert('Por favor complete el campo "' + fieldLabel + '" con una dirección válida.');
  		        formField.value = '';
  		        formField.focus();
                result = false;
  		    }
  		break;
    }
    return result;
  }
}

function validateForm(formName){
  switch (formName){
    case 'formulario':
// FORM 1 ------------------------------------------------------
	  if (!validRequired(formulario.nombre,"Nombre y Apellido","str")){return false;}
	  if (!validRequired(formulario.email,"Email","eml")){return false;}
	  // if (!validRequired(formName.edad,"Teléfono","num")){return false;}
	  if (!validRequired(formulario.comentario,"Comentario","strnum")){return false;}
      return true;
      break;

    case 'otroForm':
// FORM 2 ------------------------------------------------------
      
	  return true;
	  break;
  }
}