function init_dw_Scroll() {
    var wndo = new dw_scrollObj('wn', 'lyr1', 't1');
    wndo.setUpScrollControls('scrollLinks');
    
    // code for hiding scroll arrows
    wndo.on_scroll = wndo.on_glidescroll = function () {
        // set id's to match your doc's (images or containing elements)
        var el = document.getElementById('down_aro');
        if (wndo.x == -wndo.maxX) {
            el.style.visibility = 'hidden';
        } else {
            el.style.visibility = 'visible';
        }
	  // id for up arrow
        el = document.getElementById('up_aro');
        if (wndo.x == 0) {
            el.style.visibility = 'hidden';
        } else {
            el.style.visibility = 'visible';
        }
    }
    wndo.on_scroll(); // invoke immediately 
}


AddToInitArray(init_dw_Scroll);