function show(obj)
{
	var theCat = "cat" + obj;
	var theSubCat = "subCat" + obj;
	
	var cat = document.getElementById(theCat);
	var subCat = document.getElementById(theSubCat);
	
	if(subCat.style.display == "none") 
	{
		subCat.style.display = '';
		cat.style.background = "url('images/catlist-.jpg') no-repeat";
	}else{
		subCat.style.display = 'none';
		cat.style.background = "url('images/catlist+.jpg') no-repeat";
	}
}