JavaScript: Simple multi-timer for logging performance of an html page

gistfile1.js

	function j2timer(e){ 
		window.tdiff || (window.tdiff = []);
		window.tdlog || (window.tdlog = []);
		window.fnred || (window.fnred = function(a,b){return a-b;});
		
		//toogle statement
		if( (tdiff.length+1) % 2){
			tdiff.push( Date.now());
			return;
		}
		tdlog.push(["TIMER:", Date.now()-tdiff[tdiff.length-1], "[msec]; NOW:", Date.now(), "; WHO:", e, this.constructor.toString().split("(")[0]]);
		//commet this line out
		//console.log(tdlog.pop().join(" ") );
	}
	j2timer();

...

	j2timer();

This will result in: 
in "dbg"- mode
426TIMER: 12 [msec]; NOW: 1315664066896 ; WHO:  function DOMWindow

tdlog
[
Array[7]
0: "TIMER:"
1: 20
2: "[msec]; NOW:"
3: 1315664090219
4: "; WHO:"
5: undefined
6: "function DOMWindow"
length: 7
__proto__: Array[0]
]