function case_show(id) {

	if(document.getElementById('case_' + id + '_txt').className == 'hide') {
		var img = document.getElementById('case_' + id + '_but');
		img.setAttribute("src", 'images/case_hide.gif');
		swapClass('case_' + id + '_txt','show');
	} else {
		var img = document.getElementById('case_' + id + '_but');
		img.setAttribute("src", 'images/case_show.gif');
		swapClass('case_' + id + '_txt','hide');
	}

}



//swap an object's css class
function swapClass(id, newClass) {

	document.getElementById(id).className=newClass;

}