Just an advise. You have a lot of redundant code, this code will do exactly the same:

SET EXCLUSE OFF && This should be default, and should never be changed!!
USE street IN 0 order streetd
USE area IN 0 order areaa
USE district IN 0 
*Place a Select here, if you need to

>Hi,
>
>I have a form and I have no tables in the form's dataenvironment,
>and I open the tables in the INIT method of the dataenvironment.
>
>

>SET EXCLUSE OFF
>USE street IN 0 ALIAS street
>SELECT street
>SET ORDER TO streetd
>USE area IN 0 ALIAS area
>SELECT area
>SET ORDER TO areaa
>USE district IN 0 ALIAS district
>

>All tables are in Share mode,
>the form are set to 2- Private Data Session, but I open another form which also
>set to Private Data Sessionm, and open the Street and Area tables again, it occurs errors,
>
>How can I set the Private Data Session to let two forms have no contradiction to open same tables ?
>
>Please advise.
>Derek