There maybe some simlar questions to this but I can't see anything that really solves my problem. I would like to pass the contents of a variable in JavaScript either into a PHP variable or a html form value.
Cheers, knowing how to do both would be very helpful.
Littering your document with IDs can cause problems down the line. You should use IDs only when you really need to.
Why not do it with the DOM Level 0 forms collection?
<form name="myForm">
<input name="myInput" type="hidden" />
</form>
<script type="text/javascript">
var foo = 42;
document.forms["myForm"].elements["myInput"].value = foo;
</script>
To save a Javascript variable into a html form element, I would go using DOM:
//your target html form element must have a unique ID
var input_element = document.getElementById('unique_id');
input_element.value = google_maps_api_variable;
That's it!
You could use ajax, get/post request to the php script so that php can save the value although I haven't worked with Google Maps API. This answer should help you on DevShed
You could use hidden fields in your form.
<input type="hidden" id="testField" />
Populate the value of your hidden field with the value of your variable, and it should be there when you submit it:
var variableWithData = 42; //get this from somewhere...
document.getElementById('testField').value = variableWithData;
