var d=document;
var currentZoom = 1;
d.onkeyup = so_handleKeyEvent;

if(!document.all || window.opera) {
	so_cleanUp();
}

function so_handleKeyEvent(e) {
	keyCode = d.all?window.event.keyCode:e.keyCode;
	switch(keyCode) {
		case 107:
			if(currentZoom<2)currentZoom+=.1;
			break;
		case 109:
			if(currentZoom>=0.3)currentZoom-=.1;
			break;
		case 106:
			currentZoom = 1;
			break;
	}
	so_zoom();
}

function so_zoom() {
	document.getElementsByTagName("body")[0].style.zoom= currentZoom;
}

function so_cleanUp() {
	d.onkeyup = null;
}