function isEmailAddr(email)
{
  var result = false;
  var theStr = new String(email);
  var index = theStr.indexOf("@");
  if (index > 0)
  {
    var pindex = theStr.indexOf(".",index);
    if ((pindex > index+1) && (theStr.length > pindex+1)) result = true;
  }
  return result;
}

function validRequired(formField,fieldLabel)
{
  var result = true;
  if (formField.value == "")
  {
    alert('Por favor digite un valor para el campo "' + fieldLabel +'"!.');
    formField.focus();
    result = false;
  }
  return result;
}

function allDigits(str)
{
  return inValidCharSet(str,"0123456789");
}

function inValidCharSet(str,charset)
{
  var result = true;
  // Note: doesn't use regular expressions to avoid early Mac browser bugs
  for (var i=0;i<str.length;i++)
  if (charset.indexOf(str.substr(i,1))<0)
  {
    result = false;
    break;
  }
  return result;
}

function validEmail(formField,fieldLabel,required)
{
  var result = true;
  if (required && !validRequired(formField,fieldLabel)) result = false;
  if (result && ((formField.value.length < 3) || !isEmailAddr(formField.value)) )
  {
    alert("Digite una direccion correcta de email en la forma: nombre@sitio.com");
    formField.focus();
    result = false;
  }
  return result;
}

function validNum(formField,fieldLabel,required)
{
  var result = true;
  if (required && !validRequired(formField,fieldLabel)) result = false;
  if (result)
  {
    if (!allDigits(formField.value))
    {
      alert('Digite un numero para el campo "' + fieldLabel +'" !.');
      formField.focus();
      result = false;
    }
  }
  return result;
}

function validInt(formField,fieldLabel,required)
{
  var result = true;
  if (required && !validRequired(formField,fieldLabel)) result = false;
  if (result)
  {
    var num = parseInt(formField.value,10);
    if (isNaN(num))
    {
      alert('Digite un numero para el campo "' + fieldLabel +'" !.');
      formField.focus();
      result = false;
    }
  }
  return result;
}

function validDate(formField,fieldLabel,required)
{
  var result = true;
  if (required && !validRequired(formField,fieldLabel)) result = false;
  if (result)
  {
    var elems = formField.value.split("/");
    result = (elems.length == 3); // should be three components
    if (result)
    {
      var month = parseInt(elems[0],10);
      var day = parseInt(elems[1],10);
      var year = parseInt(elems[2],10);
      result = allDigits(elems[0]) && (month > 0) && (month < 13) &&
               allDigits(elems[1]) && (day > 0) && (day < 32) &&
               allDigits(elems[2]) && ((elems[2].length == 2) || (elems[2].length == 4));
    }
    if (!result)
    {
      alert('Digite una fecha en la forma MM/DD/YYYY para el campo "' + fieldLabel +'" !.');
      formField.focus();
    }
  }
  return result;
}

function validateForm(theForm)
{
  if (!validEmail(theForm.txtemail,"Correo Electrónico",true)) return false;
  
  var mensajin = 0;
  {
    if (theForm.txtpara.value == "") mensajin = 1
    else if (theForm.txtcalle.value == "") mensajin = 1
    else if (theForm.txtnumero.value == "") mensajin = 1
    else if (theForm.txtcolonia.value == "") mensajin = 1
    else if (theForm.txtciudad.value == "") mensajin = 1
    else if (theForm.txtdelmun.value == "") mensajin = 1
    else if (theForm.txtcp.value == "") mensajin = 1
    else if (theForm.txtemail.value == "") mensajin = 1
    else if (theForm.txtphone.value == "") mensajin = 1
	else if (theForm.txtcomentarios.value == "") mensajin = 1;

    if (mensajin == 1)
    {
      alert('Por favor indique todos los datos requeridos.');
      theForm.txtpara.focus();
      return false;
    } 
  }
  return true;
}