You have two select lists named teamtype:
<label for="teamtype"></label>
Type of team:
<select name="teamtype" id="teamtype" onchange="WA_FilterAndPopulateSubList(teamsignup_WAJA,MM_findObj('teamtype'),MM_findObj('teamID'),0,0,false,': ')">
<option value="">-- select --</option>
<option value="1">Business</option>
<option value="6">Community/Eco-team</option>
<option value="2">Congregation</option>
<option value="4">Government Agencies</option>
<option value="5">Non-profit</option>
<option value="3">Schools</option>
</select>
<label for="teamtype"></label>
<select name="teamtype" id="teamtype">
<option value="">-- select --</option>
<option value="1">Business</option>
<option value="6">Community/Eco-team</option>
<option value="2">Congregation</option>
<option value="4">Government Agencies</option>
<option value="5">Non-profit</option>
<option value="3">Schools</option>
</select></td>
the second one is causing the error.