function processKeyPress(evt) {
	evt=evt||(window.event||"");
	switch(evt.keyCode) {
	// page down
	case 33:
		if (window.addEventListener) {
			evt.preventDefault();
			evt.stopPropagation();
		} else {
			evt.returnValue = false;
			evt.cancelBubble = true;
		}
		ui_id = (document.ui_id?document.ui_id:'');
		previous(ui_id);
		break;
	// carriage return
	// page up	
	case 13:
	case 34:
		if (window.addEventListener) {
			evt.preventDefault();
			evt.stopPropagation();
		} else {
			evt.returnValue = false;
			evt.cancelBubble = true;
		}
		ui_id = (document.ui_id?document.ui_id:'');
		sendCommand('user_form','next_ui',ui_id);
		break;
	}
}

function createEventListener() {
	// mozilla and friends
	if (window.addEventListener) {
		window.addEventListener('keydown', processKeyPress, false);
	}
	 // IE
	else if (document.body.attachEvent) {
			document.body.attachEvent("onkeydown", processKeyPress);
	}
}

createEventListener();