1) Add the below script in the app/design/frontend/your theme/default/template/catalog/product/list/toolbar.phtml
<script>
jQuery(document).ready(function(){
if(!jQuery('#current').length){
jQuery("body").append('<input type="hidden" name="current" id="current" value="1" />');
jQuery("body").append('<input type="hidden" name="next" id="final" value="<?php echo $this->getLastPageNum(); ?>" />');
jQuery(window).scroll(function(event){
setTimeout(function()
{
var current_val=parseInt(jQuery("#current").val());
var final_val=parseInt(jQuery("#final").val());
var next_val=parseInt(current_val)+1;
if(final_val>current_val){
jQuery("#ajax-load").css("display","block");
jQuery.ajax({
url: "<?php echo $this->getPagerUrl(); ?>?p="+next_val,
async:false,
success: function(html){
var $result = jQuery(html).find('.products-grid').children();
jQuery(".products-grid").append($result);
jQuery("#ajax-load").css("display","none");
jQuery("#current").val(next_val);
}
});
}
});
});
}
});
</script>
2) Add image tag to show ajax loader in the app/design/frontend/ultimo/default/template/catalog/product/list.phtml path
<div id="ajax-load" style="display:none"><img src="<?php echo $this->getSkinUrl('images/ajax-loader.gif', array('_secure'=>false)); ?>" /></div>



3. Select 'Custom' from the Resource Access drop-down and select 'CMS' from the list of resources
4. In First three steps, we created Roles and selected resources to those role.
8. Then select newly created role from the list of roles.