private string BuildParams(ParameterCollection parameters)
{
StringBuilder sb = new StringBuilder("function(store,options){if (!options.params){options.params = {};};");
sb.AppendFormat("Ext.apply(options.params,{0});", parameters.ToJson(2));
sb.AppendFormat("Ext.applyIf(options.params,{0});", parameters.ToJson(1));
sb.Append("}");
return sb.ToString();
}