Click the checkbox to mark all checkbox using javascript and php

<script type="text/javascript">

    function checkAll(checkId){

        var inputs = document.getElementsByTagName("input");

        for (var i = 0; i < inputs.length; i++) {

            if (inputs[i].type == "checkbox" && inputs[i].id == checkId) {

                if(inputs[i].checked == true) {

                    inputs[i].checked = false ;

                } else if (inputs[i].checked == false ) {

                    inputs[i].checked = true ;

                }

            } 

        } 

    }

</script>

 

<table width="70%" border="1" cellspacing="0" cellpadding="1">

    <tr>

        <th align="left">

            <input type="checkbox" id="chk_new"  onclick="checkAll('chk');" >

        </th>

        <th align="left">Name</th>

        <th align="left">Mobile</th>

   </tr>

   <tr>

       <td><input type="checkbox" id="chk" value="1" name="chk[]"  ></td>

       <td>Rony David</td>

       <td>0765-999772</td>

   </tr>

   <tr>

       <td><input type="checkbox" id="chk"  value="2" name="chk[]" ></td>

       <td>Shown Mark</td>

       <td>0765-9990772</td>

   </tr>

</table>