<p><button class="w3-btn w3-blue w3-round" onclick="getLocation()">Try It</button></p>
<div id="mapholder"></div>
<script src="https://maps.google.com/maps/api/js?key=AIzaSyBu-916DdpKAjTmJNIgngS6HL_kDIKU0aU"></script>
<script>
var x=document.getElementById("demo");
function getLocation()
  {
  if (navigator.geolocation)
    {
    navigator.geolocation.getCurrentPosition(showPosition,showError);
    }
  else{x.innerHTML="Geolocation is not supported by this browser.";}
  }

function showPosition(position)
  {
  var lat=position.coords.latitude;
  var lon=position.coords.longitude;
  var latlon=new google.maps.LatLng(lat, lon)
  var mapholder=document.getElementById('mapholder')
  mapholder.style.height='250px';
  mapholder.style.width='100%';

  var myOptions={
  center:latlon,zoom:14,
  mapTypeId:google.maps.MapTypeId.ROADMAP,
  mapTypeControl:false,
  navigationControlOptions:{style:google.maps.NavigationControlStyle.SMALL}
  };
  var map=new google.maps.Map(document.getElementById("mapholder"),myOptions);
  var marker=new google.maps.Marker({position:latlon,map:map,title:"You are here!"});
  }

function showError(error)
  {
  switch(error.code) 
    {
    case error.PERMISSION_DENIED:
      x.innerHTML="User denied the request for Geolocation."
      break;
    case error.POSITION_UNAVAILABLE:
      x.innerHTML="Location information is unavailable."
      break;
    case error.TIMEOUT:
      x.innerHTML="The request to get user location timed out."
      break;
    case error.UNKNOWN_ERROR:
      x.innerHTML="An unknown error occurred."
      break;
    }
  }
</script>