var ua = navigator.userAgent.toLowerCase();
if (ua.indexOf(" chrome/") >= 0 || ua.indexOf(" firefox/") >= 0 || ua.indexOf(' gecko/') >= 0) {
	var StringMaker = function () {
		this.str = "";
		this.length = 0;
		this.append = function (s) {
			this.str += s;
			this.length += s.length;
		}
		this.prepend = function (s) {
			this.str = s + this.str;
			this.length += s.length;
		}
		this.toString = function () {
			return this.str;
		}
	}
} else {
	var StringMaker = function () {
		this.parts = [];
		this.length = 0;
		this.append = function (s) {
			this.parts.push(s);
			this.length += s.length;
		}
		this.prepend = function (s) {
			this.parts.unshift(s);
			this.length += s.length;
		}
		this.toString = function () {
			return this.parts.join('');
		}
	}
}