jQuery Grid Plugin - jqGrid

Currently to pass additional parameters to the URL which loads the grid I use the following

$("#gridname").jqGrid('setGridParam',{postData:{addvalOne:'SomeValuel'},search:true});
$("#gridname").trigger("reloadGrid");

As an example of where I use it

.navButtonAdd('pager',{caption:"",title:"Export",buttonicon:"ui-icon-disk",onClickButton:function(){
                                                                $("#listings").jqGrid('setGridParam',{postData:{export:'excel'},search:true});
                                                                $("#listings").trigger("reloadGrid")
                                                                  },
                                position:"last"
                                });