3. Create an input field that can call javascript functions to populate the data, and a span that will hold the error message

<input name=“calendarName” type=“text” id=“calendarName” onblur=”doesCalendarExist(‘<?php echo bloginfo(‘url‘); ?>’, ‘span1′, ‘calendarName’, ‘submitCalendarAdd’);“/>

<span id=“span1″ class=”formError”></span>

4. Create a PHP function that will read the data passed from the ajaxObject. Die() statements will pass JavaScript back to the page. The dieString variable is super useful to be able to add lots of different DOM changes.

function wec_ajax_doesCalendarExist(){

$confirmationField = $_POST['confirmationField'];

$calendarName = $_POST['calendarName'];

$submitButton = $_POST['submitButton'];

$calendars = calendarDA::getAllcalendars();

$exists = false;

foreach($calendars as $calendar){

if(strcasecmp($calendar['calendarName'], $calendarName) == 0){

$exists = true;

}

}

if($exists){

$dieString = “document.getElementById(‘”. $confirmationField .“‘).innerHTML=’This calendar already exists!’;”;

$dieString .= “document.getElementById(‘”. $submitButton .“‘).disabled = true;”;

die($dieString);

}

else{

$dieString = “document.getElementById(‘”. $confirmationField .“‘).innerHTML=”;”;

$dieString .= “document.getElementById(‘”. $submitButton .“‘).disabled = false;”;

die($dieString);

}

}

5. Add a WordPress Action to the init() that maps the sack action to the PHP function. you have to add “wp_ajax_” to the beginning of your action name from sack. the second argument is the name of your function that this action will call

add_action(‘wp_ajax_doesCalendarExist’, ‘wec_ajax_doesCalendarExist’ );