[jQuery] resetting target based on responseText

[Lionel Martelly]

I am using the code below to check a condition in a php. Is there a way, 
based on the response to:
1-either change the target
2-or make it return true?

I am doing some complex form validation that can only be done in the php, 
then display the callback errors in a div. Problem is if the php does not 
detect any errors and submit goes thru, the resulting page is also 
displaying in the same div. So I need to get rid of target

$(document).ready(function() {
var options = {target: '#error'}
$('#form').submit(function() {
        $(this).ajaxSubmit(options);
return false;
});
});