jQuery Simple minutes countdown timer

countdownize.js

//	jQuery Simple minutes countdown timer
//	https://gist.github.com/beshur/7872704
//	@beshur
$.fn.countdownize = function() {
	if (typeof window.page_var == "undefined") window.page_var = {};
	this.each(function(i) {
		var obj = $(this);


		// assumes integer seconds are here
		var delta = obj.data("time");

		var minutes = Math.floor(delta / 60) % 60;
		var seconds = delta - minutes*60;

		obj.tpl = '<span class="e_digit">{ins}</span>'
		obj.data("curtime", delta);
		page_var.timer = {};
		page_var.timer[i] = window.setInterval(function() {
			var delta = obj.data("curtime") - 1 || 0;
			obj.data("curtime", delta);

			var minutes = Math.floor(delta / 60) % 60;
			var seconds = delta - minutes*60;

			minutes = minutes.toString();
			seconds = seconds.toString();

			var html = '';
			if (minutes.length > 1) {
				html += obj.tpl.replace("{ins}", minutes[0]);
				html += obj.tpl.replace("{ins}", minutes[1]);
			} else {
				html = obj.tpl.replace("{ins}", minutes[0]);
			}
			html += obj.tpl.replace("{ins}", ":");
			if (seconds.length < 2) {
				html += obj.tpl.replace("{ins}", "0");
				html += obj.tpl.replace("{ins}", seconds[0]);
			} else {
				html += obj.tpl.replace("{ins}", seconds[0]);
				html += obj.tpl.replace("{ins}", seconds[1]);
			}
			
			obj.html(html).removeClass("lock");
			if (delta == 0) {
				window.clearInterval(page_var.timer[i]);
				return;
			}

		}, 1000);
	})
}