Enable/Disable datepicker using jquery in mvc.

$("#txtcurrentdate").datepicker("enable");
$("#txtcurrentdate").datepicker("disable");
This disables the entire textbox. So may be you can use datepicker.destroy() instead:

$(document).ready(function() {
    $("#ddlsearch").change(function() {
        if ($(this).val() == "Required Date" || $(this).val() == "Submitted Date") {
            $("#txtcurrentdate").datepicker();
        }
        else {
            $("#txtcurrentdate").datepicker("destroy");
        }
    }).change();
});

Find first element of second td of second tr.

<table>
<tr>
<td>
<input type="text" value="Test" name="txttest" maxlength="200" id="txttestfrom_1" class="inputSmall left valid" onchange="return GetValue(this);">
</td>
<td>
<input type="text" value="Test" name="txttest" maxlength="200" id="txttestto_1" class="inputSmall left
valid" onchange="return GetValue(this);">
<input type="text" value="Test" name="txttest" maxlength="200" id="txttestMax_1" class="inputSmall left valid" onchange="return GetValue(this);">
</td>
<td>
<input type="text" value="Test" name="txttest" maxlength="200" id="txttestdata_1" class="inputSmall left valid" onchange="return GetValue(this);">
</td>
</tr>
<tr>
<td>
<input type="text" value="Test" name="txttest" maxlength="200" id="txttestfrom_2" class="inputSmall left valid" onchange="return GetValue(this);">
</td>
<td>
<input type="text" value="Test" name="txttest" maxlength="200" id="txttestto_2" class="inputSmall left valid">
<input type="text" value="Test" name="txttest" maxlength="200" id="txttestMax_2" class="inputSmall left valid" onchange="return GetValue(this);">
</td>
<td>
<input type="text" value="Test" name="txttest" maxlength="200" id="txttestdata_2" class="inputSmall left valid" onchange="return GetValue(this);">
</td>
</tr>
</table>

<script>
function GetValue(obj)
{

alert($(obj).closest('tr').next('tr').find('td:nth-child(2) > input:nth-child(1)').attr("id"));
}

</script>



OutPut:

txttestto_2