帮我解释下这几个代码 ASP的

<%
set rs=server.createobject("adodb.recordset")
sql="select * from yanzheng where username='"&username&"'"
rs.open sql,conn,1,2
set rs=nothing
old=oyfqm(trim(request("old")))
new1=oyfqm(trim(request("new1")))
new2=oyfqm(trim(request("new2")))
if new1<>"" or new2<>"" then
if old="" then
response.Write "<script language=javascript>{window.alert('报错：在修改新密码前必须输入原密码!');window.history.go(-1);}</script>"
else if old<>rs("password") then
response.Write "<script language=javascript>{window.alert('报错：您输入的原密码错误，要修改密码必须核实原密码!');window.history.go(-1);}</script>"
end if
end if
end if
if new1<>""and new2<>"" then
if new1<>new2 then
response.Write "<scrip

<%
set rs=server.createobject("adodb.recordset")
sql="select * from yanzheng where username='"&username&"'"
rs.open sql,conn,1,2 '以上几行是说创建recordset查询数据库
set rs=nothing '释放内存,这里其实应该不需要这句!
old=oyfqm(trim(request("old")))
new1=oyfqm(trim(request("new1")))
new2=oyfqm(trim(request("new2"))) '以上是几个变量赋值.意思是从form获取传递过来的数据,并用trim去除左右空格复制给变量如NEW1.)OYFQM是自己定义的函数,我不知道什么意思
if new1<>"" or new2<>"" then 如果变量1和变量2不为空
if old="" then '如果OLD为空
response.Write "<script language=javascript>{window.alert('报错：在修改新密码前必须输入原密码!');window.history.go(-1);}</script>"
else if old<>rs("password") then
response.Write "<script language=javascript>{window.alert('报错：您输入的原密码错误，要修改密码必须核实原密?');window.history.go(-1);}</script>"
end if
end if