function switchVisibility(element) {
var ele = document.getElementById(element)
if(ele.style.display == "none") {
document.getElementById(element + 'minusimage').style.display = '';
document.getElementById(element + 'plusimage').style.display = 'none';
ele.style.display = "";
} else {
document.getElementById(element + 'minusimage').style.display = 'none';
document.getElementById(element + 'plusimage').style.display = '';
ele.style.display = "none";
}
}