MVC 3 Helper for Hover Images...

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Web.Routing;

namespace HoverImageHelper.Helpers
{
    public static class ImageButtons
    {
        public static MvcHtmlString ImageButton(this HtmlHelper helper, string imageName, string actionName)
        {
            return ImageButton(helper, imageName, actionName, null);
        }
        
        public static MvcHtmlString ImageButton(this HtmlHelper helper, string imageName, string actionName, string controllerName)
        {
            return ImageButton(helper, imageName, actionName, controllerName, null);    
        }

        public static MvcHtmlString ImageButton(this HtmlHelper helper, string imageName, string actionName, string controllerName,  object routeValues)
        {
            //Gets the action name and routes
            var urlHelper = new UrlHelper(helper.ViewContext.RequestContext);
            var url = urlHelper.Action(actionName, controllerName, routeValues);

            //Creates the image tag
            var imgTag = new TagBuilder("img");
            var imageUrl = string.Format("/Content/Images/Buttons/{0}.png", imageName);
            imgTag.Attributes.Add("src", imageUrl);
            imgTag.Attributes.Add("onmouseover", "this.src='" + imageUrl.Replace(".", "_hover.") + "'");
            imgTag.Attributes.Add("onmouseout", "this.src='" + imageUrl + "'");
            imgTag.Attributes.Add("border", "0");

            //Creates the link tag
            TagBuilder imglink = new TagBuilder("a");
            imglink.MergeAttribute("href", url);
            imglink.InnerHtml = imgTag.ToString(TagRenderMode.SelfClosing);

            return MvcHtmlString.Create(imglink.ToString());
        }
    }
}