var current = false;
var switchoff = false;

function hide_pd(){
	if(current) document.getElementById('PD_'+current).style.visibility = 'hidden';
	document.getElementById('PDx_'+current).style.backgroundPosition = '0px 0px';
	switchoff = false;
	}

function pd( id ){
	if(id && switchoff) {
	window.clearTimeout(switchoff);
	hide_pd();
	}
	if(id){
	document.getElementById('PD_'+id).style.visibility = 'visible';
	document.getElementById('PDx_'+id).style.backgroundPosition = '0px -32px';
	current = id;
	}
	if(!id){
	switchoff = window.setTimeout("hide_pd()", 250);
	}
}