Google Maps database near points

Hi ,
what is the MySQL 5.0 query needs to select geo
coordinates( latitude,longitude) from locations database
within a radius of 100 miles around this center :


map.setCenter(new GLatLng(".$initial_lat.",".$initial_lng.") ; 

how to display the markers in the Google Maps ?
Please I tried before the distance calculation of My SQL :


(3963*acos(cos(radians($initial_lat))*cos(radians(lat))*cos(radians(lng)- 
radians($initial_lng))+sin(radians($initial_lat))*sin(radians(lat)))) 
AS distance FROM agoda_hotel 
WHERE agoda_hotel.country_id = 205 
HAVING distance < 100 

however it’ s not select locations nearby the center above
correctly. I am newbie in MySQL programming and may be I
could not found the exact function.
thanks.

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