Jquery JQGrid - 如何设置网格标题单元格的对齐方式

JQuery JQGrid - 如何设置网格标题单元格的对齐方式？

html
    
    
    
    
    
    

javascript
$(document).ready(function() {
    $("#grid").jqGrid({
        url: "data.json",
        datatype: "json",
        colModel: [
            { name: "id", label: "ID", align: "center" },
            { name: "name", label: "Name", align: "center" },
            { name: "age", label: "Age", align: "center" },
            { name: "email", label: "Email", align: "center" }
        ],
        pager: "#pager",
        rowNum: 10,
        rowList: [10, 20, 30],
        sortname: "id",
        sortorder: "asc",
        viewrecords: true,
        gridview: true,
        autoencode: true,
        caption: "Sample Grid"
    });
});