code: function _fnLog( settings, level, msg, tn )
  	{
  		msg = 'DataTables warning: '+
  			(settings!==null ? 'table id='+settings.sTableId+' - ' : '')+msg;
  	
  		if ( tn ) {
  			msg += '. For more information about this error, please see '+
  			'http://datatables.net/tn/'+tn;
  		}
  	
  		if ( ! level  ) {
  			// Backwards compatibility pre 1.10
  			var ext = DataTable.ext;
  			var type = ext.sErrMode || ext.errMode;
  	
  			if ( type == 'alert' ) {
  				alert( msg );
  			}
  			else {
  				throw new Error(msg);
  			}
  		}
  		else if ( window.console && console.log ) {
  			console.log( msg );
  		}
  	}
docs: Log an error message
  @param {object} settings dataTables settings object
  @param {int} level log error messages, or display them to the user
  @param {string} msg error message
  @param {int} tn Technical note id to get more information about the error.
  @memberof DataTable#oApi