function isAlpha(c){
   return elem(c,"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ");
}
function isLower(c){return isAlpha(c) && c==c.toLowerCase()};
function isUpper(c){return isAlpha(c) && c==c.toUpperCase()};
function elem(c,str){
   for (var i=0;i<str.length;i++)
      if (c == str[i])
         return true;
   return false;
}