load XML data in a hashtable

I'm pretty new in using XML, can someone help me find a way to load data from an XML file to a hashtable.  I need it in a hashtable because i need to have a key value pair.  The reason i also have two items per value is i need to do a rotation everythime a user goes to my site it will rotate the image. I've never done this before and not sure if it's possible.  I'm using asp.net in C#

I also can't use the .net adrotator because I don't want the image to change when the user refreshes the page that's why I choose to do the hash table.  That way i can set it so that when the user is inside cake.aspx, i can grab the data from the hashtable that belongs under the items that have the "cake" value.

XML:

located inside App_Data(cake.xml)

 
   cake1.gif
   cake.aspx

 
   cake2.gif
   cake2.aspx

 
   donut1.gif
   donut.aspx

 
   donut2.gif
   donut2.aspx



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code is located inside the App_Code (cakerotate.cs)

public static void CakeRotate()
{
XMLDocument objGetCake = new XMLDocument();
objGetCake.Load(HttpContext.Current.Server.MapPath("~/App_Data/cake.xml"));

if (null != objGetCake)
{
     XMLNode objNode = (XmlNodeList objList in objGetCake)
          {
                //this is where I get stuck because I'm not sure how to load the XML Data inside the HashTable.
          }
}

 }

Any help would be much appreciated.

Thanks in advance