#extra_controls, #scrollbar { 
    display: block; /* initially display:none; to hide from incapable */
    }
	
div.content { /* hide content to be swapped in */
	position: absolute;
	visibility: hidden;
	left:0px;
	top:0px; 
	}

div#up {
	position: absolute;
	left: 0;
	top: 0;
	}

div#down {
	position: absolute;
	left: 0;
	bottom: 0;
	}

/* so no gap or misplacement due to image vertical alignment
font-size:1px in scrollbar has same effect (less likely to be removed, resulting in support issues) */
div#scrollbar img {
    display:block; 
    } 
    
/* for safari, to prevent selection problem */
div#scrollbar, div#track, div#dragBar, div#up, div#down {
    -moz-user-select: none;
    -khtml-user-select: none;
	}