ArcGIS Polygon Search

--Polygon Search for Transport Spending

URL: http://xxxxx/arcgis/rest/services/TransportSpending/MapServer/0/query

Filter Geometry: {"rings":[[[272276.48887,6179999.947118772],[385469.50589442987,6361478.599097537]]]}

Geometry Type: Polygon

Input Spatial Reference (WKID): 28356

Spatial Relationship: contains

Where clause: empty

I found this by sniffing the traffic of a page that I created by copying and pasting the html in http://resources.esri.com/help/9.3/arcgisserver/apis/javascript/arcgis/help/jssamples_start.htm#jssamples/util_simplify.html