// форматирует вывод числа, аналог number_format() в PHP
function js_number_format(number, decimals, dec_point, thousands_sep){
  var exponent = "";
  var numberstr = number.toString ();
  var eindex = numberstr.indexOf ("e");
 var i, z;
  if(eindex > -1){
    exponent = numberstr.substring (eindex);
    number = parseFloat (numberstr.substring (0, eindex));
  }

  if(decimals != null){
    var temp = Math.pow (10, decimals);
    number = Math.round (number * temp) / temp;
  }
  var sign = number < 0 ? "-" : "";
  var integer = (number > 0 ?
      Math.floor (number) : Math.abs (Math.ceil (number))).toString ();

  var fractional = number.toString ().substring (integer.length + sign.length);
  dec_point = dec_point != null ? dec_point : ".";
  fractional = decimals != null && decimals > 0 || fractional.length > 1 ? (dec_point + fractional.substring (1)) : "";
  if(decimals != null && decimals > 0){
    for(i = fractional.length - 1, z = decimals; i < z; ++i)
      fractional += "0";
  }

  thousands_sep = (thousands_sep != dec_point || fractional.length == 0) ?
                  thousands_sep : null;
  if(thousands_sep != null && thousands_sep != ""){
  for (i = integer.length - 3; i > 0; i -= 3)
   integer = integer.substring (0 , i) + thousands_sep + integer.substring (i);
  }
  return sign + integer + fractional + exponent;
}


function check_email_format (email)
{
  var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
  return filter.test(email);
}