openlayers and geoext

Question

I have created a WMS layer in geoserver. I have added that WMS layer using openlayers and geoext. The WMS layer is displaying, but when I zoom in, the layer disappears and when zoomed out the layer is again visible as a dot.

My code is:

 new OpenLayers.Layer.WMS("Layers",
                "http://localhost:8080/geoserver/cite/wms",
                {
                    "LAYERS":'layer1',
                   srs:'EPSG:3857',
                   transparent: true,
                    format: "image/png"
                }, 

                {
                    isBaseLayer: false,

                    buffer: 0,
                    // exclude this layer from layer container nodes
                    displayInLayerSwitcher: false,
                    visibility: false
                }
            )

Answer 1

You can use a maxExtent for your map. In combination with a 3rd-party background-layer this can prevent the problem you described.

var extent = new OpenLayers.Bounds(-2003750.34, -2003750.34, 2003750.34, 2003750.34);

map = new OpenLayers.Map("map", {
        maxExtent: extent
});