//function to display or hide a given element

function showHideItems(myItem){

//this is the ID of the hidden item
var myItem = document.getElementById(myItem);


if (myItem.style.display != "none") {
//items are currently displayed, so hide them

myItem.style.display = "none";

}
else {

//items are currently hidden, so display them
myItem.style.display = "block";

}
}