# OpenLayers bounds with Lat/Long

I am using a custom map with the TMS in OpenLayers. I know my high/low latitude and longitude points. In other words I know the exact bounds of my map image in Lat/Long.

Is there a way to use lat/long in the bounds? Or do I have to convert to Mercator? My bounds are pretty small - it only covers maybe 10 square miles and then I want to be able to draw circles on the map at specific lat/long locations - like draw a circle to highlight a gas station.

I am just a bit confused about the Bounds portion. Here is my code this far - use they Mercator bounds just to get my image to display:

``````function loadmap() {
var get_my_url = function (bounds) {
var res = this.map.getResolution();
var x = Math.round((bounds.left - this.maxExtent.left) / (res * this.tileSize.w));
var y = Math.round((this.maxExtent.top - bounds.top) / (res * this.tileSize.h));
var z = this.map.getZoom();

var path = z + "_" + x + "_" + y + "." + this.type;
var url = this.url;
if (url instanceof Array) {
url = this.selectUrl(path, url);
}
return url + path;
}

var options = {
maxExtent: new OpenLayers.Bounds(-20037508.3427892, -20037508.3427892, 20037508.3427892, 20037508.3427892),
numZoomLevels: 5,
units: 'm',
projection: "EPSG:900913",
displayProjection: new OpenLayers.Projection("EPSG:4326")
};

var map = new OpenLayers.Map(
'wissmap',
options
);

var layer = new OpenLayers.Layer.TMS(
'Aerial',
'/custom/maps/',
{
type: 'jpg',
getURL: get_my_url
}
);