function calcWMZ(form) 
{   
  var wmz_from = form.wmz_from.value;
  var usd = form.usd.value;
  if  (isEmpty(usd)) usd = 1; 

  if (isInteger(wmz_from))
  {
    var result = 0;
 
    if (wmz_from < 100)
    {
      result =  wmz_from * 0.955;
    }
    else
    if (wmz_from < 500)
    {                                         
      result =  wmz_from * 0.96;
    }
    else
    if (wmz_from < 1000)
    {
      result =  wmz_from * 0.965;
    }
    else
    if (wmz_from > 1000)
    {
      result =  wmz_from * 0.97;
    }

   form.wmz_to.value = Math.round(result * usd);
  }
}


function calcRUR(form) 
{   
 var rur_from = form.rur_from.value;
 var usd = form.usd.value;
 if  (isEmpty(usd)) usd = 1; 

 if (isInteger(rur_from))
 {
   var result = rur_from / usd;
 
   if (result < 100)
   {
     result =  result * 0.97;
   }
   else
   if (result < 500)
   {                                         
     result =  result * 0.98;
   }
   else
   if (result < 1000)
   {
     result =  result * 0.982;
   }
   else
   if (result < 3000)
   {
     result =  result * 0.985;
   }
   else
   if (result >= 3000)
   {
     result =  result * 0.99;
   }

   form.rur_to.value = Math.round(result);
 }
}



function isInteger (s)
{
  var i;

  if (isEmpty(s))
  if (isInteger.arguments.length == 1) return 0;
  else return (isInteger.arguments[1] == true);

  for (i = 0; i < s.length; i++)
  {
    var c = s.charAt(i);

    if (!isDigit(c)) return false;
  }

  return true;
}

function isEmpty(s)
{
  return ((s == null) || (s.length == 0))
}

function isDigit (c)
{
  return ((c >= "0") && (c <= "9"))
}