求助：ASP日期范围查询

输入时间范围：2011-7-6到2011-9-9可以查询到，要是输入2011-7-6-2011-10-26就查询不到了，日期要是一样可以查到，
只要日期位数不一样，就查询不到，我的页面语句是这样写的，

读取页面输入值 ：sq_time=trim(Request("sq_time")) sq_time2=trim(Request("sq_time2"))

查询语句我用了三种方法，都不能实现，三种语句分别为为：

rst.open "select * from [seal] where sq_time BETWEEN #"&sq_time&"# and #"&sq_time2&"# order by id desc",conn,1,1
rst.open "select * from [seal] where sq_time>=#"&sq_time&"# and sq_time<=#"&sq_time2&"# order by id desc",conn,1,1
rst.open "select * from [seal] where sq_time>='"&sq_time&"' and sq_time<='"&sq_time2&"' order by id desc",conn,1,1

请大家告诉我，要怎么写才能正常查询呢？

VBScript code

rst.open "select * from [seal] where datediff('d',sql_time,#"&sql_time&"#)<=0 and datediff('d',sql_time,#"&sql_time2&"#)>=0 order by id desc",conn,1,1