function limitText(limitField, limitNum) {
    if (limitField.value.length > limitNum) {
        limitField.value = limitField.value.substring(0, limitNum);
    } 
}

function numbersonly(e, decimal) {
  var key;
  var keychar;
  if (window.event) { key = window.event.keyCode; }
  else if (e) { key = e.which; }
  else { return true; }
  keychar = String.fromCharCode(key);
  if ((key==null) || (key==0) || (key==8) ||  (key==9) || (key==13) || (key==27) ) { return true; }
  else if ((("0123456789").indexOf(keychar) > -1)) { return true; }
  else if (decimal && (keychar == ".")) { return true; } else return false;
}