Virtual Earth MAP ASP.NET MAP Control Find Issue

 Hi,

I am using   Microsoft.Live.ServerControls.VE   Map Control on my ASP.Net 3.5 application.
I am passing list of lat/lng attributes & I am getting map. But the issue is when I am trying to find some thing on map.
For example

I have MAP displaying 10 properties  on map. Now my concern is How I can Find the list of schools on map respective to these properties. Virtual earth Map server control  provided 2 overloaded method to find information on map.
map.Find(what, where, findType, shapeLayer, startIndex, numberOfResults, showResults, createResults, useDefaultDisambiguation, setBestMapView)
&
map.Find(What,Where)
Now my problem is what should I put in place of "WHERE" in above method. Because I don't know the area. NULL & empty is not working in this case.
Please help in to resolve this iss ...