function showHideItems(myItem, myButton){

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

	 //this is the ID of the plus/minus button image
	var myButton = document.getElementById(myButton);

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

	myItem.style.display = "none";

 	swapImage(myButton,"plus");
}
else {
//items are currently hidden, so display them
	myItem.style.display = "block";
	
	swapImage(myButton,"minus");
	}
 }

//function to swap an image based on its current state
 function swapImage(myImage, state) {

if (state == "minus") {
	myImage.src = "images/minus.gif";
	myImage.title = "Hide"
	myImage.alt = "Hide"
 }

else {
	myImage.src = "images/plus.gif";
	myImage.title = "Show "
	myImage.alt = "Show"
	}
}