automatically Get user gps coordinates in php without user inputs

Question

I'm looking for a less complicated way to get user coordinates. please have a look at my example below. I'm trying by all means to avoid using IP address as they do not give me the correct address information.

$lat = "-25.702064";//I need to replace these hard coded coordinates by ones I've picked up automatically.
$lng = " 28.263665";
 $url = 'http://maps.googleapis.com/maps/api/geocode/json?latlng='.trim($lat).','.trim($lng).'&sensor=false';
 $json = @file_get_contents($url);
 $data=json_decode($json);
 $status = $data->status;
 if($status=="OK")
 {
   $address =  $data->results[0]->formatted_address;
  $addr = explode(",",$address);
  echo "Street :".$addr[0]."<br>";
  echo "Suburb :".$addr[1]."<br>";
  echo "Region :".$addr[2]."<br>";
  echo "Postal code :".$addr[3]."<br>";
  echo "Country :".$addr[4]."<br>";
 }
 else
 {
   //return false;
   echo "No available data to display about address";
 }