Edit in JSFiddle

$(document).ready(function() {
    $('input[type="text"]').keyup(function(e){
        if(e.keyCode == 27) {
            $(this).val('');
        }
    });
});

<table>
<tr>
    <td>First Name:
    </td>
    <td><input type='text' id='txtFName'/ >
    </td>
</tr>
<tr>
    <td>Last Name:
    </td>
    <td><input type='text' id='txtLName'/ >
    </td>
</tr>
<tr>
    <td>Age:
    </td>
    <td><input type='text' id='txtAge'/ >
    </td>
</tr>
<tr>
    <td>Email:
    </td>
    <td><input type='text' id='txtEmail'/ >
    </td>
</tr>
<tr>
    <td colspan="2" style='text-align:center;'><input type="button" id="btnSubmit" value=" Submit ">
    </td>
</tr>
</table>