Change HTML attribute value using onclick event in jquery

Question

Hello guys I just want to ask how can i change html attribute values using an event in jquery. For example I have a user list filled with information and there is a button update and cancel. The user information is READONLY but when the user click the button update it will remove the READONLY attribute in my textboxes.

Here's my simple code:

  <div style="display: none" id="form_edit" class="k-content">
        <table border="0">

            <tr>
                <td>
                    &nbsp;&nbsp;&nbsp;<label>P.O. #</label>
                </td>
                <td>
                    &nbsp;&nbsp;&nbsp;<input type="text" name="po" value="<?php echo $order_code; ?>" readonly="readonly" />
                </td>
                <td>
                    &nbsp;&nbsp;&nbsp;<label>SUPPLIER NAME</label>
                </td>
                <td>
                    &nbsp;&nbsp;&nbsp;<input type="text" name="suppliername" value="<?php echo $sname; ?>" readonly="readonly"" />
                </td>
                <td>
                    &nbsp;&nbsp;&nbsp;<label>Contact Person</label>
                </td>
                 <td>
                    &nbsp;&nbsp;&nbsp;<input type="text" name="person" value="<?php echo $contactperson; ?>" readonly="readonly" />
                </td>
            </tr>

            <tr>
                <td>
                    &nbsp;&nbsp;&nbsp;<label>TIN #</label>
                </td>
                <td>
                    &nbsp;&nbsp;&nbsp;<input type="text" name="tin" value="<?php echo $tin; ?>" readonly="readonly" />
                </td>
            </tr>

            <tr>
                <td colspan="6" style="text-align: right">

                    <input type="button" value="UPDATE" class="k-button" id="submit_form"/>
                    <input type="button" value="HIDE" class="k-button" id="close_form"/>
                </td>
            </tr>


        </table>
    </div>

My jquery

  $("a[name=edit_order]").click(function (e) {
        $("#window_edit").data("kendoWindow").open();
        e.preventDefault();
    });

    $("a[name=remove_order]").click(function (e) {
        $("#window_remove").data("kendoWindow").open();
        e.preventDefault();
    });

    /*here's the part that will remove the readonly attribute but how can i do that?
    $("#update_supplier").click(function(){
        $("#form_edit").show({
            effect: "blind",
            animation: 1000
        });

        $("#update_supplier").hide({
            effect: "fade",
            animation: 1000,
        });
    });

    /*if close bring back again the readonly*/
    $("#close_form").click(function(){
        $("#form_edit").hide({
            effect: "blind",
            animation: 1000
        });

         $("#update_supplier").show({
            effect: "fade",
            animation: 1000,
        });
    });

Answer 1

Try this

$('#submit_form').on('click', function () {
    $('input["readonly"]').removeAttr('readonly');
});

Answer 2

Try this code :

$('#submit_form').on('click', function () {
    $('input[name="suppliername"]').removeAttr('readonly');
});

Check my edit.