stat=new Array(); 
function changeMain(id){
	objParent=document.getElementById(id); 
	objDaughter=document.getElementById('D'+id); 
	if (stat[id]!=1) {stat[id]=1; objDaughter.style.display='block';} 
	else {
			if(stat[id]==1){stat[id]=0; objDaughter.style.display='none'; 
			}
	}  
}