How to assign div value to php variable using Jquery Ajax call - ajax

Question

I have a href tag, in that i wrote onclick func,
<?php the_post_thumbnail('portfolio_thumbs'); ?>
in the onclick() function the code is,
<script type="text/javascript">
function doThumb(temp)
var tempThmb = temp;
document.getElementById("selectedResult").innerHTML=tempThmb;
return tempThmb;
}
</script>
the returned value, im printing it in an empty div.
<div id="selectedResult" name="selectedResult"></div>';
Now my issue is, im getting the result in the empty div, but i have to pass the value of the div to $my_postid.
$my_postid = "Should pass the value here";//This is page id or post id
$content_post = get_post($my_postid);
How can i achieve this do i have to use ajax jquery, kindly help me....

Answer 1

This is not possible in the way you are doing. PHP is server side language and javascript is client side. One way to do this is to send an ajax request at onclick event of your image. And send the id in ajax request. The ajax will get the post on the base of that id and will return you. Then you can show that post content any where.
update after receiving code of questioner
You don't need to do initial operation in your function. Just change it as below.
function doThumb(temp) {
var $mainCats=temp;
alert ($mainCats);
$.ajax ( {
url:"<?php bloginfo('wpurl'); ?>/wp-admin/admin-ajax.php",
type:'POST',
data:'action=my_special_ajax_callc&main_catidc=' + $mainCats,
onsuccess : function(data) {
$("#selectedResults").removeAttr("disabled");
$("#selectedResults").append(data);
}
} );
}