Got Problem With Connection To Access Database

i run asp in my standalone pc, using access2003 as the database, like this:

i hv 3 pages,
1st page, i open the database, extract data from database for display(closing the connection using "recordset.close" and "conn.close").... then i have form input for users to input some information...and post to 2nd page

2nd page, this page may load N times depending on the user input in first page...for each time loading, i hv form input for users to input the detailed information. and for 2nd to Nth loading, i will get previous page's form input information(request.form("xxx")), then insert into database ("conn.execute")and close it("conn.close")...

last page, this page get Nth loading user input information for the 2nd page, then open database, insert into database("conn.execute") and close it("conn.close")...

now the problem is like this...database can not store data correctly:
it did not insert N rows into database....maybe N+1 or N+M...randomly...because same data is insert more than once, so some rows are just duplicated...it seemes that the connection just can not be closed and do insertion more than once during each time the 2nd page is loading or during the last page is loading...

can anyone help me to find out the problem? any suggestion?