ArcGIS MapServer Locations can Be ZOOMED to by Variable selection

How does one or can one Zoom to an area within an ArcGIS MapServer using a Variable to return from a SQL Database Lat and Long?

I can return both Lat and Long for a site selected, but how do i get the Map to ‘Zoom into’ that area once selected?

Example Site A Selected - Lat is 35.1 and Lng is -86.3. Now get the Map to to zoom to that area?