OpenLayers.Layer.WMS

The WMS layer allows one to connect to a WMS server to obtain images. Params are available as a hash on the layer object, however, all keys are upper-cased automatically for maximum compatibility with WMS servers, so a parameter which is set as 'layers' will be uppercased to LAYERS. Where 'layer' is your Javscript variable for the layer, layer.params.LAYERS is the value of the layers param as set by the constructor.

If you wish to change params, you should use mergeNewParams, rather than accessing the parameters directly.

* Constructor
  OpenLayers.Layer.WMS(name, url, params, options) -- URL is the base URL to the layer. Params is a set of params to be included in the HTTP Request. Options is a set of options, extending the parameters of the layer.

* Methods
  getURL({OpenLayers.Bounds|bounds}) -- {String} -- Returns a WMS URL for the given bounds based on the properties of the layer.
  All other methods are inherited from {OpenLayers.Layer.Grid}
  
* Options 
  isBaseLayer -- WMS layers default to being base layers unless one of their parameters is 'transparent':'true'.