var ot = null
t1 = "  [ + ]"
t2 = "  [ - ]"

function menuCollapse() {
	myParent = document.getElementById("inv")
	ot = document.getElementById("ch1")

	if (myParent.style.display=="block") {
		myParent.style.display="none";
		ot.innerHTML = t1
	} else {
		myParent.style.display="block"
		ot.innerHTML = t2

	}

}