function CheckNonEmptyField(field)
{
  if (field.value.length=="")
  {
    return(false);
  }
  return(true);
}

function validateEmail(email)
{
 var atPosition, dotPosition;
 
 if(email != "")// allow empty field
 {
   atPosition=email.indexOf("@");
   dotPosition=email.lastIndexOf(".");
   if(atPosition >0 && dotPosition > atPosition+1 && dotPosition < (email.length-2))
   {
       return(true);
   }
 }
 return(false);
}

function validatePassword(field)
{
  if (field.length >= 6)
  {
    if (field.charAt(0).toLowerCase()>='a' && field.charAt(0).toLowerCase()<='z')
    {
      return true;
    }

    var j, numaric = field;
    for(j=0; j<numaric.length; j++)
    {
      var alphaa = numaric.charAt(j);
      var hh = alphaa.charCodeAt(0);
      if((hh > 47 && hh<59) || (hh > 64 && hh<91) || (hh > 96 && hh<123))
      {
      }
      else
      {
        return false;
      }
    }
    return true;
  }
  return false;
}

function checkLength(field, max_length)
{
  if (field.length > max_length)
  {
    return true;
  }
  return false;
}

function trimField(field, max_length)
{
  if (field.value.length > max_length)
  {
    field.value = field.value.substring(0, max_length);
  }
}