One Button Works Well while the Other One Doesn't

Hi:

Would anybody know why button No. 1 Sends the right Search parameters to its corresponding Results page while Button No. 2 does NOT?

Button No. 1:

<td><img src="WA_DataAssist/images/Pacifica/GetAttPercent.gif" width="118" height="27" alt="GetAttPercent.gif" onclick="document.getElementById('WADASearchForm').setAttribute('action','-stuattend_ResultsPercent.php');document.getElementById('WADASearchForm').submit();" /></td>

Button No. 2:

<td width="30%"><img src="Images/Buttons/PeriodPerf_Results.gif" width="118" height="27" alt="PeriodPerf_Results.gif" onclick="document.getElementById('WADASearchForm').setAttribute('action','-stuperf_PeriodResultsG1.php');document.getElementById('WADASearchForm').submit();" /></td>

Both lines of code look OK. Their syntax correspond to one another's. Yet, Button No. 1 shows the desired results on the stuattend_ResultsPercent.php page while Button No. 2 does NOT show the desired results on the stuperf_PeriodResultsG1.php.

Any idea why?

Any suggestion would be very appreciated.

Thank you for your attention