I have dropdown box i can select multiple values.But The same thing is not working for Mozilla.Its working fine in IE.Is this a html issue or javascript issue?

My code is :


<!--Statement Date Range-->
<table border="0" cellspacing="0" cellpadding="2" width="100%">
<tr>
<td><input type="radio" name="rad" id="rad_from1" onclick="enablefromdays();" checked/>From</td>
<td>To</td>
<td>&nbsp;</td>
</tr>

<tr>
<td style="padding-left:23px;">
<form name="form2" action="">
<input value="dd/mm/yyyy" name="todaysdate" id="statementdate_from" type="text" size="10" /> <a href="javascript:void(0)"> <img src="../images/calendar.gif" alt="Calendar" title="Calendar" border="0"/></a>
</form>
</td>
<td>
<form name="form3" action="">
<input value="dd/mm/yyyy" name="todaysdate2" id="statementdate_to" type="text" size="10" /> <a href="javascript:void(0)"><img src="../images/calendar.gif" alt="Calendar" title="Calendar" border="0"/></a>
</form>
</td>
<td><input type="checkbox" name="" id=""/> Include Business Days Only</td>
</tr>

<tr>
<td><input type="radio" name="rad" id="rad_from2" onclick="enablefromdays1();"/>From</td>
<td>To</td>
<td>&nbsp;</td>
</tr>

<tr>
<td style="padding-left:23px;">
<select size="1" multiple id="or_from" disabled>
<option>0</option>
<option>- 1</option>
<option>- 2</option>
<option>- 3 </option>
<option>- 4 </option>
<option>- 5</option>
<option>- 6</option>
<option>- 7 </option>
<option>- 8 </option>
<option>- 9</option>
<option>- 10</option>
<option>- 11 </option>
<option>- 12 </option>
<option>- 13</option>
<option>- 14</option>
<option>- 15</option>
<option>- 16</option>
<option>- 17</option>
<option>- 18</option>
<option>- 19</option>
<option>- 20</option>
<option>- 21</option>
<option>- 22</option>
<option>- 23</option>
<option>- 24</option>
<option>- 26</option>
<option>- 27</option>
<option>- 28</option>
<option>- 29</option>
<option>- 30</option>
</select>
<span class="space5">&nbsp</span>Days
</td>
<td>
<select size="1" multiple id="or_to" disabled>
<option>0</option>
<option>+ 1</option>
<option>+ 2</option>
<option>+ 3 </option>
<option>+ 4 </option>
<option>+ 5</option>
<option>+ 6</option>
<option>+ 7 </option>
<option>+ 8 </option>
<option>+ 9</option>
<option>+ 10</option>
<option>+ 11 </option>
<option>+ 12 </option>
<option>+ 13</option>
<option>+ 14</option>
<option>+ 15</option>
<option>+ 16</option>
<option>+ 17</option>
<option>+ 18</option>
<option>+ 19</option>
<option>+ 20</option>
<option>+ 21</option>
<option>+ 22</option>
<option>+ 23</option>
<option>+ 24</option>
<option>+ 26</option>
<option>+ 27</option>
<option>+ 28</option>
<option>+ 29</option>
<option>+ 30</option>
</select>
<span class="space5">&nbsp</span>Days
</td>
<td>&nbsp;</td>
</tr>
</table>
<!--Statement Date Range-->

Thanks in advance