问JavaScript AM/PM时间比较

EN

var fromdt = "2013/05/29 12:30 PM";
var todt = "2013/05/29 01:30 AM";
var from = new Date(Date.parse(fromdt));
var to = new Date(Date.parse(todt));

alert(from);
alert(to)

if (from > to) alert("From");
else alert("To");

function get_time() {
  var time_t = "";
  var d = new Date();
  var cur_hour = d.getHours();

  cur_hour < 12 ? (time_t = "am") : (time_t = "pm");
  cur_hour == 0 ? (cur_hour = 12) : (cur_hour = cur_hour);
  cur_hour > 12 ? (cur_hour = cur_hour - 12) : (cur_hour = cur_hour);
  var curr_min = d.getMinutes().toString();
  var curr_sec = d.getSeconds().toString();
  if (curr_min.length == 1) {
    curr_min = "0" + curr_min;
  }
  if (curr_sec.length == 1) {
    curr_sec = "0" + curr_sec;
  }
  $("#updatedTime").html(
    cur_hour + ":" + curr_min + ":" + curr_sec + " " + time_t
  );
  alert(cur_hour + ":" + curr_min + ":" + curr_sec + " " + time_t);
}