数据连接问题，急~~
程序段：
dim rs as adodb.recordset
set rs=nothing
rs.open "select * from student where id= ' " &trim(txtID) & " ' ",cn,3,3
rs.close
提示错误：对象变量或with块变量未设置

怎么回事啊？求高手告诉我解决的办法

[解决办法]
dim rs as new adodb.recordset