visdat.buildMap = function(mapName, zoomLevels, projection, displayProjection, mapUnits, maxExtent, restrictedExtent, centerMap, startZoom, minScale){
	var map = new OpenLayers.Map(mapName, {
		controls: [],
		numZoomLevels: zoomLevels,
	    projection: projection,
	    displayProjection: displayProjection,
	 	units: mapUnits,
	 	//minScale: minScale,
		maxExtent: maxExtent,
		restrictedExtent: restrictedExtent,
		allOverlays: false,
		resolutions: [156543.03390000001, 78271.516950000005, 39135.758475000002, 19567.879237500001, 9783.9396187500006, 4891.9698093750003, 2445.9849046875001, 1222.9924523437501, 611.49622617187504, 305.74811308593752, 152.87405654296876, 76.43702827148438, 38.21851413574219, 19.109257067871095, 9.5546285339355475, 4.7773142669677737, 2.3886571334838869, 1.1943285667419434, 0.59716428337097172, 0.29858214168548586]
	});

	//Control
 	map.addControl(new OpenLayers.Control.Navigation({'zoomWheelEnabled': true}));
	map.addControl(new OpenLayers.Control.Attribution());
	
	return map;
};

visdat.f_maxExtent = function (minx,miny,maxx,maxy) {
	var ol_extent = new OpenLayers.Bounds(minx,miny,maxx,maxy);
	return ol_extent;
};

visdat.f_restrictedExtent = function (minx,miny,maxx,maxy) {
	var ol_extent = new OpenLayers.Bounds(minx,miny,maxx,maxy);
	return ol_extent;
};

visdat.f_projection = function (epsg) {
	var projection = new OpenLayers.Projection(epsg);
	return projection;
};

visdat.f_centerMap = function (minx,miny,maxx,maxy){
	var centerX = (minx+maxx)/2;
	var centerY = (miny+maxy)/2;
		 
	var centerMap = new OpenLayers.LonLat(centerX, centerY);
	return centerMap;
};