Custom jQuery Tools Scrollable plugin for making sure it doesn't pass the end.

scrollable.lockable.js

/**
 *
 * jQuery Tools / Scrollable **Lockable** Plugin
 * @author Joe Critchley, Motionlab Marketing Ltd.
 *
 */
 
(function($) {		

	var t = $.tools.scrollable; 
	
	t.lockable = {	
		conf: {
			size: 4
		}
	};	
	
	// jQuery plugin implementation
	$.fn.lockable = function(conf) { 
		
		var opts = $.extend({}, t.lockable.conf, conf), ret;
		var undefined;
		
		this.each(function() {		
				
			var api = $(this).data("scrollable");			
			if (api) { ret = api; }
			
			var currentIndex = 1,
				prevIndex,
				locked = false;

			api.onBeforeSeek(function(e, i) {
				
				currentIndex = i-1;

				if((api.getIndex() >= (api.getSize() - opts.size)) 
				&& (prevIndex <= currentIndex && locked === false)) {
					e.preventDefault();
					locked = true;
				}
				else {
					locked = false;
				}
				
				prevIndex = currentIndex;
				
			});
						
			$(api.getConf().prev).click(function(e) {
				e.preventDefault();
			});
			
			$(api.getConf().next).click(function(e) {
				e.preventDefault();
			});

		});
		
		return opts.api ? ret : this;
		
	}; 
	
})(jQuery);