function DownloadData(format) {

    var geometry = null;
    var geomtype = null;
    var breakclause = "&breakField=COLLECTION_DATE_YEAR";
    // markers are a lot simpler than polygons
    if (_searchGeometryObject.GeometryType == "marker") {
        geometry = _searchGeometryObject.Geometry.x + "," + _searchGeometryObject.Geometry.y;
        geomtype = "esriGeometryPoint";
    }
    // For polygons, create the correct json query string
    else if (_searchGeometryObject.GeometryType == "polygon" || _searchGeometryObject.GeometryType == "envelope") {
        var i = null;
        geometry = "{\"rings\" : ";
        geometry += "[[";
        for (i=0;i<_searchGeometryObject.Geometry.getVertexCount()-1;i++) {
            geometry += "[" + _searchGeometryObject.Geometry.getVertex(i).x + "," + _searchGeometryObject.Geometry.getVertex(i).y + "],";
        }
        geometry += "[" + _searchGeometryObject.Geometry.getVertex(0).x + "," + _searchGeometryObject.Geometry.getVertex(0).y + "]";
        geometry += "]],";
        geometry += "\"spatialReference\" : {\"wkid\" : 4326}}";
        geomtype = "esriGeometryPolygon";
    }
    var httpRequest = CreateRESTRequest(format, geometry, geomtype, encodeURIComponent(_searchPrefs.CreateWhereClause()) + breakclause);
    
    if (format == 'html') {
        window.open(httpRequest); // Open HTML content in new window.
    }
    else {
        self.frames['downloadFrame'].location.href = httpRequest; // Open other format types in the iframe so the zip file pops up.
    }
}