How to get current timestamp in JavaScript?

Following Javascript code returns current date and timestamp of client. This is quite handy for Open UI development, one can call following code from console.log() method to record the invocation sequence which is otherwise very difficult.

function displayTime(str2) {  
    var str = "";
    var currentTime = new Date()
    var hours = currentTime.getHours()
    var minutes = currentTime.getMinutes()
    var seconds = currentTime.getSeconds()
    var milliseconds = currentTime.getMilliseconds()
    if (minutes < 10) {
        minutes = "0" + minutes
    }
    if (seconds < 10) {
        seconds = "0" + seconds
    }
    str += hours + ":" + minutes + ":" + seconds + ":" + milliseconds;
    return str2 + ": " + str;
    }

Siebel Open UI Example:

 console.log("PR Invoked" + displayTime("@"));

Hope it helps.