function dd(obj){
	if(document.getElementById){
		document.getElementById(obj).style.display=='none'?document.getElementById(obj).style.display='':document.getElementById(obj).style.display='none';
	} else if (document.all){
		document.all(obj).style.display=='none'?document.all(obj).style.display='':document.all(obj).style.display='none';
	} else if(document.layers){
		document.layers[obj].display=='none'?document.layers[obj].display='':document.layers[obj].display='none';
	}
}