Absolute path for images in Datalist

Hi

I have a Datalist where I want to retrive Images from a folder and I have done URL rewritting so Images is not displaying when I write something like this:

 <asp:HyperLink ID="HyperLink1"  ImageUrl='<%# Bind("Product_Image", "~/ProductImages/{0}") %>'
                                                NavigateUrl='<%#"http://localhost:49524Mysite/Product/" + stringToBase64String(Eval("ProductID").ToString())%>' CommandName="IMG" CommandArgument='<%# Eval("ProductID")%>'  runat="server"></asp:HyperLink>

Images is displaying when I write something like this:

 <asp:HyperLink ID="HyperLink1"  ImageUrl='<%# Bind("Product_Image", "http://localhost:49524Mysite/ProductImages/{0}") %>'
                                                NavigateUrl='<%#"http://localhost:49524/Mysite/Product/" + stringToBase64String(Eval("ProductID").ToString())%>' CommandName="IMG" CommandArgument='<%# Eval("ProductID")%>'  runat="server"></asp:HyperLink>

I don't want to write whole URL.

Please let me know how to resolve this. Its very urgent