var prev="";
function showhide(id)
{
	
	var current = id;

	sh=document.getElementById(id);

	if(prev!="" && current!=prev)
	{
		prevsh = document.getElementById(prev);
		prevsh.style.display = "none";
		document.getElementById('img_'+prev).src='images/plus1.gif';
	}

	if (sh.style.display!='')
	{
		sh.style.display='';
		document.getElementById('img_'+id).src='images/minus1.gif';
		prev = current;
	}

	else
	{
		sh.style.display='none';
		document.getElementById('img_'+id).src='images/plus1.gif';
	}
}