.mask_dx  
        {
        	width:325px;
            height:252px;
            background-image:url(/images/timeline/bg_dx.png);
        	background-repeat: no-repeat;
        	}
        .mask_sx  
        {
    	    width:325px;
            height:252px;
            background-image:url(/images/timeline/bg_sx.png);
    		background-repeat: no-repeat;
        	}