function ImageAlpha(img) {   //³z©ú
     //alert('filter=' + img.style.filter);
        if (img.style.filter=='') {
		      img.style.filter = "Alpha(opacity=50,finishOpacity=0,style=0)";
		    }else{
		    	img.style.filter = "";
		    }
	}
	
	function ImageGray(img) {   //¶Â¥Õ
     //alert('filter=' + img.style.filter);
        if (img.style.filter=='') {
		      img.style.filter = "Gray()";
		    }else{
		    	img.style.filter = "";
		    }
	}