function showspan(span) {
	dtype = document.getElementsByName(span)[0].style.display;

	if (dtype == "none")
	document.getElementsByName(span)[0].style.display = "block";
	else
	document.getElementsByName(span)[0].style.display = "none";
	
}

function ccspan(span) {
	for (a=1;a<tab_span.length;a++) {
		
		document.getElementById(tab_span[a]).style.display='none';
	}
		
	document.getElementById(span).style.display='block';

}