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;
}