Passing html 5 variable into input

I am trying to pass the users lattitude and longitude into the directions input on the tab the below code ads a button that requests the users location and displays it but i cant work out how to set it as a variable and echo it via php.
I did echo the word cool though.

               <?php if ($geodir_map_options['enable_map_direction']) { ?>

                    <input type="text" id="<?php echo $map_canvas_name; ?>_fromAddress" name="from" class="textfield"
                           value="<?php echo cool; ?>"
                           onblur="if (this.value == '') {this.value = '<?php echo ENTER_LOCATION_TEXT; ?>';}"
                           onfocus="if (this.value == '<?php echo ENTER_LOCATION_TEXT; ?>') {this.value = '';}"/>
                    <input type="button" value="<?php _e('Get Directions', 'geodirectory'); ?>"
                           class="<?php echo $map_canvas_name; ?>_getdirection" id="directions"
                           onclick="calcRoute('<?php echo $map_canvas_name; ?>')"/>
                   <button onclick="getLocation()">Near Me</button>
<p id="demo"></p>

<script>
var x = document.getElementById("demo");

function getLocation() {
    if (navigator.geolocation) {
        navigator.geolocation.getCurrentPosition(showPosition);
    } else { 
        x.innerHTML = "Geolocation is not supported by this browser.";
    }
}

function showPosition(position) {
    x.innerHTML = position.coords.latitude +","+ position.coords.longitude;	
}
</script>
                    <script>
                        <?php if(geodir_is_page('detail')){?>
                        jQuery(function () {
                            gd_initialize_ac();
                        });

Any help would be great from anyone! Thankyou 🙂