function toggleCat(a) { 
   	if(!a)return;    
        ar = a.parentNode.getElementsByTagName('ul');
   		p=ar[0];
       img=a.parentNode.getElementsByTagName('img')[0];			   
	if(p.style.display == 'none') {
		p.style.display = 'block';
		img.src = '/common/shared/images/icon_contract.gif';
	} else {
		p.style.display = 'none';
		img.src = '/common/shared/images/icon_expand.gif';
	}
}