odbc_free_result

Hi, I'm a newbie and I'm currently porting a system coded in another language to PHP4. Here's a question about the internals of PHP: The manual states that it's not necesary to do odbc_free_result() because PHP will free all used resources upong script completion. Ok, but what if I reuse (overwrite) the ODBC result identifier like this:

    $ex=odbc_exec($jg_difolt, "SELECT ...");
    ....
    //Here... I don't free the resource
    $ex=odbc_exec($jg_difolt, "SELECT ...");
    ....
    //Now... I free the resource...
    odbc_free_result($ex);

I guess both resources are freed, but I just want to make sure because I do this all the time (because the old code I'm porting does it (because it's ok to do it in _that_ language) (and I'm too lazy to rework it)). Thanks in advance. Regards, Ernesto