jqgrid 怎么改变编辑框的位置和大小

$("#list").jqGrid({
datatype: "local",
mtype:"POST",
url:"",
colNames:[],
colModel:[
],
rowNum:15,
rowList:[15,20,30],
gridview:true,
pager: $('#pagerb'),
viewrecords: true,
rownumbers: true,
rownumWidth: 30,
postData:"",
height:'250px',
width: 860,
//autowidth:true,
shrinkToFit:false,
forceFit:true,
emptyrecords:"没有符合数据",
caption: ""
}).navGrid('#pagerb',{
add: true,
addtext: "添加 ",
del: false,
edit: true,
edittext: "修改 ",
position: "left",
view: true,
viewtext: "查看 ",
search: false,
refreshtitle: "刷新",
refreshtext: "刷新 ",
alertcap: "提示信息"
},{ //edit 编辑时
top : 10, //位置
left: 200, //位置
height:480, //大小
width:750, //大小

},{ //add 添加时
top : 10,
left: 200,
height:480,
width:750,

},{ //del
},{ //search
},{ //view
}
)