I have xml file like following for displaying ads using asp:AdRotator in asp

```
<?xml version="1.0" encoding="utf-8" ?>
<Advertisements>
 <Ad>
<ImageUrl>~/xxx/xxx.jpg</ImageUrl>
<NavigateUrl>xxx</NavigateUrl>
<AlternateText>xxx</AlternateText>
<Impressions>100</Impressions>
 </Ad>
</Advertisements>

```

now i want to add new data between ... tag in asp.net using vb how to do that..?