从输入通过ajax获取变量到外部php

Question

I have this in index.php I would like to get my input data (range) as variable into my nova.php. When I am trying to use $range = $_GET['range']; in nova.php it shows : Undefined index: range. I think, I should put something like data:{range: range} into myAjax function. But of course it's not working

<input id="range" type="text" name="range" class="enter" value="">
<input type="button" onclick="myAjax()" value="Show nearby" />

my ajax

function myAjax() {
  $.ajax({
       type: "POST",
       url: 'nova.php',
       data:{action:'call_this'},
       success:function(html) {
         alert(html);
       }
  });
}

and my nova.php:

<?php
if($_POST['action'] == 'call_this') {
$con=mysqli_connect("localhost","tech","151987","portnew");
// Check connection 
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$range = $_GET['range']; 
// Perform queries
$query = $con->query("SELECT ( 6371 * acos( cos( radians(53.216908) )*
cos( radians( lat ) ) * cos( radians( lng ) - radians(7.453240) ) + 
sin( radians(53.216908) ) * sin( radians( lat ) ) ) ) AS distance,     
port_name FROM ports HAVING distance < '".$range."' ORDER BY distance LIMIT 0 , 20; ");

while ($row = $query->fetch_assoc()) {
    $port_list[] = $row['port_name'];
}
echo json_encode($port_list);
}
?> 

So basically this script is looking for nearby locations based on latitude, logitude. It's working when I put ...HAVING distance < 150 ORDER BY..., but I would like to set my range in input, and not using static range

Answer 1

Check this jsFiddle

and you ajax function should be

function myAjax() {
var range = document.getElementById('range').value;
  $.ajax({
       type: "POST",
       url: 'nova.php',
       data:{action:'call_this',range:range},
       success:function(html) {
         alert(html);
       }
  });
}

at php code change this line

$range = $_GET['range'];

to

 $range = $_POST['range'];

also the input of type range should have a value defined. ex value="100". don't leave it blank