isIE = document.all ? true:false;
function newOption() {
   opt = isIE ? document.createElement("OPTION") : new Option();
   return opt;
}
function addOption(objSelect, objOption) {
   if(isIE)
      objSelect.add(objOption, objSelect.length);
   else {
      objSelect.length++;
      objSelect.options[objSelect.length-1] = objOption;
   }
}
var numbers = ".0123456789 ";
function isNumeric(str) {
   for(i=0; i<str.length; i++) {
      if(numbers.indexOf(str.substring(i, i + 1)) == -1)
         return false;
   }
   return true;
}