[jQuery] jQuary Ajax

[jQuery] jQuary Ajax


Hello everyone,
Is it possible to send ajax call for somefile.php and get just value
of one php variable generated by that server
script?
Example:
    $.post( blog.php?task=checkname,
     {ime:$(\"#ime\").val()},
     function(msg){
     alert(msg);
});
This ajax call will get whole page ( blog.php?task=checkname) as a
result but I want value of just one variable.
I know I could create a separate file "ajaxCheck.php" that would
return HTML I could reuse in my javaScript
but I want to solve this this way.
Im probbably using wrong method POST & GET. Should I be using jSON?!
How do I use it for this purposes
Thank you
Luka