Check all checkboxes

<input id="chkall" type="checkbox" title="Select/Clear All" onchange="getselect(this)"/>

for (int i = 0; i < Model.lst.Count; i++)

{

@Html.CheckBoxFor(m => m.lst[i].Aid, new { @class="chk", id="chk" })

}

<script type="text/javascript">

   

    function getselect() {

        if (document.getElementById('chkall').checked) {

            $('.chk').prop('checked', true);

        }

        else {

         

            $('.chk').prop('checked', false);

           

        }    

    }

        

</script>