About ASP SQL problem

Hi all, got SQL syntex error during asp coding...
i define a variable named "talbeName" and assign it value thru form submit...then combine this variable with another string to form an SQL string...then send it to database using recordset...below are the code:
-------------------------------------------------------
.......
tableName=request.form("tableName")
SQLStr="select * from "&tableName
set conn=Server.CreateObject("ADODB.Connection")
conn.Open "............."
set rs = Server.CreateObject("ADODB.recordset")
rs.open SQLStr, conn,3,3
.......
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the error says: [Microsoft][ODBC SQL Server Driver][SQL Server]Line 1: Incorrect syntax near 'from'.

my tableName's value is "system_lookup"---this table does exist in database...when i write my code as SQLStr="select * from system_lookup", everything works fine.

So wat's wrong with my coding:SQLStr="select * from "&tableName?

When you response.write SQLStr, is the output the same as what you expect it to be?

When you response.write SQLStr, is the output the same as what you expect it to be?

YES it is

the qs table definately exists?

try conn.execute(SQLstr)