how to cache third party images in silverlight .

[skumar.snl]

hi,

We are showing Video with slides(images) in silverlight .Our images come from amazon server now we want to cache these images before starting Video.

our code is given below:

private void LoadImage(string ImageURL)
{

WebClient downloader = new WebClient();
downloader.OpenReadCompleted += new OpenReadCompletedEventHandler(downloader_OpenReadCompleted);
string fileName = ImageURL;
downloader.OpenReadAsync(new Uri(fileName, UriKind.Absolute));
}

void downloader_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
{

// Create a new BitmapImage and load the stream

BitmapImage loadedImage = new BitmapImage();
loadedImage.SetSource(e.Result);

}

But it gives following Error in e.Result:

System.Reflection.TargetInvocationException was unhandled by user code
Message=An exception occurred during the operation, making the result invalid. Check InnerException for exception details.
StackTrace:
at System.ComponentModel.AsyncCompletedEventArgs.RaiseExceptionIfNecessary()
at System.Net.OpenReadCompletedEventArgs.get_Result()
at Video_PowerPoint.Session.downloader_OpenReadCompleted(Object sender, OpenReadCompletedEventArgs e)
at System.Net.WebClient.OnOpenReadCompleted(OpenReadCompletedEventArgs e)
at System.Net.WebClient.OpenReadOperationCompleted(Object arg)
InnerException: System.Security.SecurityException
Message=""
StackTrace:
at System.Net.Browser.AsyncHelper.BeginOnUI(SendOrPostCallback beginMethod, Object state)
at System.Net.Browser.BrowserHttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
at System.Net.WebClient.GetWebResponse(WebRequest request, IAsyncResult result)
at System.Net.WebClient.OpenReadAsyncCallback(IAsyncResult result)
InnerException: System.Security.SecurityException
Message=Security error.
StackTrace:
at System.Net.Browser.BrowserHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult)
at System.Net.Browser.BrowserHttpWebRequest.<>c__DisplayClass5.b__4(Object sendState)
at System.Net.Browser.AsyncHelper.<>c__DisplayClass2.b__0(Object sendState)
InnerException:

Please Throw some light on this error . Is this the right way to cache image ?? Any other suggestion.