Question

Suppose the simple three input form below. Using the values of lat and lon I need to run a PHP function (already written) that creates the value I want in sitename. The current form action already works just fine, and does something completely different than my question.

<form name="w3Balltrak" class="feedbackform" action="readyget.pl" method="post"
<input type="text" id='lat' name='lat' value='' />
<input type="text" id='lon' name='lon' value='' />
<input type="text" id='sitename' name='sitename' value='' />
<input type="submit" value="Submit" /> 
</form>

My problem is I don’t know how to set the value of the sitename to the output of my PHP function. The function works great, a call to it in PHP would look like this ‘getWX($lat, $lon)’ and the return would look like this ‘MCI’.

How do I make the default value of sitename MCI immediately after the user enters a value in lon but before he hits the submit button at the end of the form?

I hope I asked this well enough for someone to understand and answer.

Answer 1

As far as i understood your question .. your answer would be ajax

<script type="text/javascript">
// wait until the document ist ready.. otherwise the 2 ids dont exist in this moment
jQuery(document).ready(function($){
    // on every change in the input fields send a request to the php
    $('#lat, #lon').live('change', function(){
        $.get("test.php", { lat: $('#lat').val(), lon: $('#lon').val() },
           function(data){
             $('#sitename').val(data);
        });            
    });
});
</script>

and in the test.php file

<?php
// if the 2 fields are not empty ... join them and return the result
if(!empty($_GET['lat']) && !empty($_GET['lon'])){
    $result = $_GET['lat'] . $_GET['lon'];
}
echo $result; 
?>

$result will then be what the jQuery function recives as “data”