Basic Question - How do I insert into two tables, one after the other?

Sorry guys, I'm relatively new at PHP, and as I've never done this before, I need to ask.

How do I correctly format the syntax below in order to insert to 2 separate tables, one after the other?

$r=query_wrapper("SELECT * FROM tblmembers WHERE mem_email = ?",$mem_email);
$rstDBEdit=mysql_fetch_assoc($r);

if($rstDBEdit)
redirect("/message.php?message=already_a_member");

$a["mem_name"] = $mem_name;
$a["mem_password"] = $mem_password;
$a["mem_email"] = $mem_email;

....

query_wrapper("INSERT INTO tblmembers SET ?%",$a);

$mem_ID = mysql_insert_id();

----------------------------------------------------

$r=query_wrapper("SELECT * FROM tblshare_adverts");
$rstDBEdit=mysql_fetch_assoc($r);

$a["share_available"] = $share_available;
$a["share_header"] = $share_header;
$a["share_description"] = $share_description;

....

query_wrapper("INSERT INTO tblshare_adverts SET ?%",$a);

$share_ID = mysql_insert_id();