Solution 1
You need to add at least one class="required" to anyone of your radio inputs, like this:
<input type="radio" name="radio-choice-1" id="radio-choice-1" value="1" class="required" />
<label for="radio-choice-1">foo</label>
<input type="radio" name="radio-choice-1" id="radio-choice-2" value="2" />
<label for="radio-choice-2">bar</label>
Working example: http://jsfiddle.net/Gajotres/a8cJA/
Solution 2
Or you can do it like this:
$(document).on('pagebeforeshow', '#index', function(){
$("#sendMessageFormContainer").validate({
rules : {
"radio-choice-1" : { required : true }
},
messages : {
"radio-choice-1" : "Please select radio button"
},
submitHandler: function (form) {
alert("Call Send Action");
}
});
$(document).on('click', '#sendMsgBtn', function(){
$("#sendMessageFormContainer").validate().form();
});
});
Working example: http://jsfiddle.net/Gajotres/HwQeY/