PHP Code:
$sql = mssql_query("SELECT * FROM TB_User WHERE StrUserId='$_POST[username]'");
$row = mssql_fetch_array($sql);
$silk = mssql_query("INSERT INTO SK_Silk(JID,silk_own,silk_gift,silk_point) VALUES ('$row[JID]','9999','0','0')");
9999 is the silk value.Tell me if this ain't working
(Add this to your .php page in case you don't know)