Validating - at least one checkbox is checked

I have a problem in validating whether at least one checkbox is checked or not.

the same code is being used for a different form and its working perfectly but I can't figure why it doesn't on this form.

this is the HTML and jquery code

if(jQuery('#MOTForm input[type=checkbox]:checked').length == 0) { 
       alert("1");
       valid = valid && false;
       $("#MOTFORMERROR").css('color', 'red');
       $("#MOTFORMERROR").html("*Choose at least one");
}else{
       $("#MOTFORMERROR").html("");
}


<td style="width: 10%;" rowspan="3">


                        <div style="padding-left:5px;">
                               <form id="MOTForm">
                                   <input name="" type="checkbox"  class="form-check-input"/> HEMS<br />
                                   <input name="" type="checkbox"  class="form-check-input"/> EMS<br /> 
                                   <input name="" type="checkbox"  class="form-check-input"/> Walk-in<br />

                               </form>
                               <p id="MOTFORMERROR"></p>
                            </div>


                        </td>

the if statement is what being run all the time not the else statement even if one or all checkboxes are checked!