Error while adding field from Add form

[Samadhan1012]

I want to add one more field height value from Add Form page along with existing name and firstname. So I have added code accordingly but gets error. Please correct me.
Index.html:
<select id="height" names ="height" class="js-example-basic-single" type="text" style="width:50%" placeholder = "";'> <option></option> <option value="System Test">System Test</option> <option value="Early FPV">Early FPV</option> <option value="FPV">FPV</option> </select>
add.php:
`$name = $mysqli->real_escape_string(strip_tags($_POST['name']));
$firstname = $mysqli->real_escape_string(strip_tags($_POST['firstname']));
$age = 20;
$lastvisit = date('Y/m/d');
$height = $mysqli->real_escape_string(strip_tags($_POST['height']));
$tablename = $mysqli->real_escape_string(strip_tags($_POST['tablename']));

$return=false;
if ( $stmt = $mysqli->prepare("INSERT INTO ".$tablename." (name, firstname, age, lastvisit, height) VALUES ( ?, ?, ?, ?, ?)")) {

$stmt->bind_param("sssss", $name, $firstname, $age, $lastvisit, $height);`

loaddata.php:
$grid->addColumn('height', 'Height', 'string');
demo.js:
` data: {
tablename : self.editableGrid.name,
name: $("#name").val(),
firstname: $("#firstname").val(),
height: $("#height").val()
},
success: function (response)
{
if (response == "ok" ) {

            // hide form
            showAddForm();   
    		$("#name").val('');
            $("#firstname").val('');
			$("#height").val('');
            message("success","Record added successfully.");
            self.fetchGrid();`

MySql database:
`height | varchar(30) | latin1_swedish_ci |   | Yes | NULL'

[jakobl]

i am facing the same problem. Have you found a solution?