How to pass a javascript variable to an html form action tag

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Javascript

HTML

web_development

I have an html form which contain name, longitude and latitude text field. The longitude and latitude are stored in a javascript variable. Do you know how pass only the latitude and longitude to a server, I mean via a url? Everytime I am submitting the form, the longitude and latitude are not passed into the url? Can anyone please tell me how to do that?

This is my code for both my javascript and html:

if (navigator.geolocation) {
var geolocation = {};
geolocation.latitude = 0;
geolocation.longitude = 0;
navigator.geolocation.getCurrentPosition(function (p) {
geolocation.latitude = p.coords.latitude;
geolocation.longitude = p.coords.longitude;           
}, function (error) {
alert("Failed to get GPS location");
});
} else {
alert("Failed to get GPS working");
}

function loc() {
document.getElementById("longitude").value = geolocation.latitude;
document.getElementById("latitude").value = geolocation.longitude;

}

html:

<form name="photo" method="post" action="url">
<label for="name">Name:</label>
<input type="text" name="name" id="Text1" value="" />
<label for="longitude">Longitude:</label>
<input type="text" name="longitude" id="longitude" />
<label for="latitude">Latitude:</label>
<input type="text" name="latitude" id="latitude" />
<label for="image">Image:</label>
<input type="text" name="image" id="image" />
<input type="submit" value="Submit" />
</form>