Question: I am creating an application where the user picks a value from a combo box, the application then selects that feature and then selects the corresponding features from a second layer, (both selections are in a different colour). What I want to do is as soon as the selection is made, the map will zoom to the envelope of the selected features. I know how to zoom to 2 individual layers (using pEnvlope.union...), but i need to do it on features.

Has anyone got any idea of the best way to do this?
(I'm using ArcGIS 9.3.1 and VBA).

Thanks

Answer: 
You could just use the [ArcMap Command](http://edndoc.esri.com/arcobjects/9.2/NET/858a508c-b771-467c-81e6-c6aa72d88f9c.htm), Zoom To Selected Features.

```
  Dim pUID As New UID
  Dim pCmdItem As ICommandItem
  ' Use the GUID of the Save command
  ' Zoom to all selected features
  pUID.Value = "{AB073B49-DE5E-11D1-AA80-00C04FA37860}"
  ' or you can use the ProgID
  ' pUID.Value = "esriArcMapUI.ZoomToSelectedCommand"
  pUID.SubType = 3
  Set pCmdItem = Application.Document.CommandBars.Find(pUID)
  pCmdItem.Execute

```
If you have info about the object, you know it's min/max X and Y's, so it's a matter of building some logic in the code tozoom to that envelope, taking into account scaling etc