The Universal World Owner's Manual

Event( "PlaceAnyBuilding", "" )
{
    $nBuildingType = $gParam[1]

    $nearestTownID = sysGetNearestTown( $gPlayerWorldX, $gPlayerWorldY )
    $numInTown = sysTownGetNumBuildingsOfType( $nearestTownID, $nBuildingType )
    if ( $numInTown >= 3 )
    {
       *msg %PLAYER% There can only be 3 of each type of building in each town
       CancelTransaction()
    }
    else
    {
	$valid = sysIsBuildingPositionValid( $nBuildingType )
	if ( $valid = 1 )
	{
		$buildingName = sysGetTextEntry()
		$constrAmount = -1
		$didAdd = sysAddBuildingWorld( $nBuildingType,$gPlayerID,$gPlayerWorldX,$gPlayerWorldY,$buildingName,$constrAmount )
	}
    }
}