var cols = new Ext.grid.ColumnModel([
new Ext.grid.RowNumberer(),
{header:'学号',dataIndex:'code'},
{header:'姓名',dataIndex:'name'},
{header:'性别',dataIndex:'sex',renderer:sexRenderer},
{header:'年龄',dataIndex:'age',align:'center'},
{header:'政治面貌',dataIndex:'political'},
{header:'籍贯',dataIndex:'origin'},
{header:'所属系',dataIndex:'professional'}
]);