//Empty field validation
function valRequired(formField,alertTextReq)
{
  var result = true;
  
  if (formField.value == "")
  {
    alert(alertTextReq);
    formField.focus();
    result = false;
  }
  
  return result;
}


//E-Mail if is not empty and if is valid format
function valEmail(formField,alertTextReq,required)
{
  var result = true;
  
  if (required && !valRequired(formField,alertTextReq))
    result = false;

  if (result && ((formField.value.length < 3) || !isEmailAddr(formField.value)) )
  {
    alert("Incorrect e-mail format, please verify");
    formField.focus();
    result = false;
  }
   
  return result;
}


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;
}

//Number if is not empty and valid type
function valNumber(formField,alertTextReq,required)
{
  var result = true;

  if (required && !valRequired(formField,alertTextReq))
    result = false;
  
   if (result)
   {
     var num = parseInt(formField.value,10);
     if (isNaN(num))
     {
       alert("Incorrect data type");
      formField.focus();    
      result = false;
    }
  } 
  
  return result;
}