function changezoom(z) {
	try {
		document.execCommand("BackgroundImageCache",false,true);
	}
	catch(err) { }
	try {
		if(typeof(window.zoom_fontsize)!="object") {
			zoom_fontsize = { min : 11, max : 15 }
		}
		var btag = document.getElementsByTagName("body")[0];
		if(btag.style && btag.style.fontSize!="") {
			var f_size = btag.style.fontSize;
		}
		var f_size = parseInt(f_size);
		if(isNaN(f_size)) {
			var f_size = zoom_fontsize.min;
		}
		var newsize = f_size+z;
		if(newsize<zoom_fontsize.min) {
			var newsize = zoom_fontsize.min;
		}
		else if(newsize>zoom_fontsize.max) {
			var newsize = zoom_fontsize.max;
		}
		btag.style.fontSize = newsize+"px";
		var today = new Date();
		var expire = new Date();
		expire.setTime(today.getTime() + 3600000*24*365);
		document.cookie = "fontsize="+escape(newsize) + ";expires="+expire.toGMTString() + ";path=/";
	}
	catch(err) { }
}