$.post is an ajax event. You are posting data by ajax so by that the page doesn't go to the communitypage.php. For the behaviour you want you have to do normal form post and not ajax post. $.post will retrive anything you echo on communitypage.php using this code.

//Note the 3rd argument is a callback.

var hash = location.hash;

$.post('communitypage.php',{hash:hash},function(data){

    alert(data);

});

Process hash on that page and alert something if u find the hash. You'd find the echo in the data

You could mod the communitypage.php to return html as below

<?php

if($isset($_POST[hash]) && strlen(trim($_POST[hash])) > 0){

    echo Hash found ::  . $_POST[hash]; 

}else

    echo No hash found;

?>

Note this will return html you can modify the response to return xml, json as per your needs.

Refer jQuery post() documentation for more info.

For the updated question

It works outside because it is called when the ajax call is made inside a function it won't because the function is not called. If you want to do that (and i don't know why) u can do like this.

function myfunction(){

    //your code goes here

}



myfunction(); //call the function so that the code in the function is called upon

Though that's an overkill unless u want to call the function over and over in the same script. If it works without a function you should do it that way.