$("#homework_student_work_list").html("<%= escape_javascript(render :partial => 'student_work/student_work_list') %>");
$("#export_student_work").replaceWith("<%= escape_javascript( link_to "导出作业成绩", student_work_index_path(:homework => @homework.id,:order => @order, :sort => @b_sort, :group => @group, :name => @name, :format => 'xls'),:class=>'hworkExport postTypeGrey', :id => 'export_student_work') %>");