asp简单问题：为什么response.write（rs1("kch")）下显示两遍

<%
sub show(xqjc)
Set rs = conn.ExeCute("select szbj from student where userName='"&session("userName")&"' and userPass='"&session("userPass")&"'")
if not rs.eof then
Set rs2 = conn.ExeCute("select kch from course where ksbj='"&rs("szbj")&"'")
else '------------------修改处
if not rs2.eof then
do while not rs2.eof
if rs2("kch")<>"" then
Set rs1 = conn.ExeCute("Select symc,kch From kb where xqjc='"&xqjc&"'")
if not rs1.eof then
do while not rs1.eof
if rs2("kch") <> rs1("kch") then
'response.write(rs1("symc"))
response.write("rs1="&rs1("kch")&" ")
response.write("rs2="&rs2("kch")&" ")
end if
rs