src_sh = '/_images/btn.plus.gif';	//var src_sh = '/html/btn.show.gif';
src_hi = '/_images/btn.minus.gif';	//var src_hi = '/html/btn.hide.gif';



function toggleDisplay(dest)
 {
	element = document.getElementById(dest).style;
	element_btn = document.getElementById(dest + 'btn');

	if (element.display=='none')
	 {
		element.display='block';
		element_btn.src = src_hi;
	 }
	else
	 {
		element.display='none';
		element_btn.src = src_sh;
	 }
 }