帮个忙asp 中Excel文件导入ACCESS数据库

这有一个参考，网上有很多类似的导入资料。
<%
dim conn
dim conn2
set conn=CreateObject("ADODB.Connection")
'.Open "Provider=Microsoft.Jet.OLEDB.4.0;Jet OLEDB:Database Password=;Data Source=C:\TestAsp\book1.mdb"
conn.Open "driver={sql server};server=.;uid=sa;pwd=jack;database=jack"

set conn2=CreateObject("ADODB.Connection")
'conn2.Open "Provider=Microsoft.Jet.OLEDB.4.0;Jet OLEDB:Database Password=;Extended properties=Excel 5.0;Data Source=C:\TestAsp\book1.xls"
conn2.Open "Provider=Microsoft.Jet.OLEDB.4.0;Extended properties=Excel 5.0;Data Source=C:\TestAsp\book1.xls"
sql = "SELECT * FROM [Sheet1$]"
set rs = conn2.execute(sql)
while not rs.eof
'sql = "insert into Table3([userId],[userName],[userPass]) values('"& fixsql(rs(0)) &"','"& fixsql(rs(1)) &"','"& fixsql(rs(2)) &"')"
sql = "insert into Table4([userName],[userPass]) values('"& fixsql(rs(0)) &"','"& fixsql(rs(1)) &"')"
conn.execute(sql)
rs.movenext
wend

conn.close
set conn = nothing
conn2.close
set conn2 = nothing

function fixsql(str)
dim newstr
newstr = str
if isnull(newstr) then
newstr = ""
else
newstr = replace(newstr,"'","''")
end if
fixsql = newstr
end function
%>
<input name="" type="button" value="测试" />

谢谢,我自己经搞好了.现在的问题是,在批量导入时.有重复的会员资料应该怎么去判断!不要在数据库中有两条或两条以上的信息存在(用户无意中批导入两次)?