Some form checkbox combinations do not work - html

Question

I have this code and can't figure out what seems to be the problem: if i select 1 & 2, 1 & 3 it's working.
But if I select 2 or 3 only then it's not working.
What seems to be the problem?
I would like to select multiple at the same time.
i think I need to put some if and else here?
But don't really know and sure how?
This is the code:
<div style="background-color:#CCDFED">
<form method="post" action="[~[*id*]~]">
<input type="hidden" name="formid" value="registrationForm" />
<table>
<tr>
<td>
<label for="termine" style="margin:0.5em">Termine:</label>
<td>
<td>
<input type="checkbox" name="termine1" value="Montag 4. Oktober 2010" eform="Termine::1"/> Montag 4. Oktober 2010 <br/>
<input type="checkbox" name="termine2" value="Mittwoch 13. Oktober 2010" /> Mittwoch 13. Oktober 2010 <br/>
<input type="checkbox" name="termine3" value="Freitag 22. Oktober 2010" /> Freitag 22. Oktober 2010 <br/>
</td>
</tr>
<tr>
<td><label for="email" style="margin:0.5em">Email:</label></td>
<td><input type="text" name="email" size="60" maxlength="60" eform="Email:email:1" /><td>
</tr>
<tr>
<td>
<label style="margin:0.5em; display:block" for="kopieren" >Bitte kopieren Sie den Anti-Spam Code ein: </label>
<img src="[+verimageurl+]" alt="verification code" border="1" style="margin:0.5em"/></td>
</td>
<td valign="top"><input type="text" name="vericode" size="20" /> </td>
</tr>
<tr>
<td rowspan="3" valign="right">
<input align="right" type="submit" name="submit" style="margin:0.5em" value="Register" />
</td>
</tr>
</table>
</form>
</div>

Answer 1

You are making them required by setting eform on all of them. Remove the ::1 eform if they are not required. I also added a validation message.
Try:
<input type="checkbox" id="termine1" name="termine[]" value="Montag 4. Oktober 2010" eform="Termine::1:Please select at least one box"/> Montag 4. Oktober 2010 <br/>
<input type="checkbox" id="termine2" name="termine[]" value="Mittwoch 13. Oktober 2010" /> Mittwoch 13. Oktober 2010 <br/>
<input type="checkbox" id="termine3" name="termine[]" value="Freitag 22. Oktober 2010" /> Freitag 22. Oktober 2010 <br/>
I am doing all of this blindly, so bear with me. Once you have submitted the form, you now need I no longer see your code for the confirmation page. All you need to change is in your report you need to use
[+termine+].

Answer 2

This might because of label is not attaching with your, checkbox, just provide Id to checkbox, please refer below
<input type="checkbox" id="termine1" name="termine1" value="Montag 4. Oktober 2010" eform="Termine::1" />
<label for="termine1"> Montag 4. Oktober 2010</label>
Hope this will resolve your issue.