javascript:
	document.addEventListener('mousedown', e => {
		if (e.button == 2 && e.target.nodeName == 'SELECT') {
			window.sst = setTimeout(function() {
				var q = prompt('Search what?', '');
				if (q === '') {
					[].forEach.call(e.target.options, o => o.style.display = '');
				}
				else if (q != null) {
					[].forEach.call(e.target.options, o => o.style.display = o.textContent.toLowerCase().indexOf(q) >= 0 ? '' : 'none');
				}
			}, 300);
		}
	});
	document.addEventListener('mouseup', e => {
		clearTimeout(window.sst);
	});
	void(0);