I have a user control

<input id="check" type="checkbox" />  
 <label>&nbsp;</label>  
<fieldset class="clearfix" id="fieldset-exception">
    <legend>Student Information</legend>
    <div class="fiveper">
        <label for="StudentID">
            Exception ID:
            <span><%=Html.EditorFor(x => x.studentid)%></span>
        </label>
        <label for="Classroom">
            Origination:
            <span><%=Html.EditorFor(model => model.Classroom)%></span>
        </label>
        <label for="Subject">
            Age:
            <span><%=Html.EditorFor(model => model.subject)%></span>
        </label>
</div>
 $('#btnAll').click(function() {
           $('#Details input[type=checkbox]').attr('checked', 'checked');
        });

I am checking all checkboxes using above code but I need to make condition here that user need to select atleast one checkbox to do something? i have other button to go other page based on this checkbox checked? can anybody tell me how to check that and how to make that condition here? Thanks thanks