End time should not be less than start time

End time should not be less than start time

HTML

<input type="text" id="txtStartTime" value="5:00 PM" />
<input type="text" id="txtEndTime" value="01:23 AM" />
<input type="button" id="btnCompare" value="Compare" onclick="Compare()" />

JavaScript

function Compare() {
    var strStartTime = document.getElementById("txtStartTime").value;
    var strEndTime = document.getElementById("txtEndTime").value;

    var startTime = new Date().setHours(GetHours(strStartTime), GetMinutes(strStartTime), 0);
    var endTime = new Date(startTime)
    endTime = endTime.setHours(GetHours(strEndTime), GetMinutes(strEndTime), 0);
    if (startTime > endTime) {
        alert("Start Time is greater than end time");
    }
    if (startTime == endTime) {
        alert("Start Time equals end time");
    }
    if (startTime < endTime) {
        alert("Start Time is less than end time");
    }
}
function GetHours(d) {
    var h = parseInt(d.split(':')[0]);
    if (d.split(':')[1].split(' ')[1] == "PM") {
        h = h + 12;
    }
    return h;
}
function GetMinutes(d) {
    return parseInt(d.split(':')[1].split(' ')[0]);
}