how to know when to release string for iphone
<p>i have this </p>

<pre><code> NSXMLParser *xmlParserf = [[NSXMLParser alloc] initWithContentsOfURL:url];
    //  NSLog(@"URL%@",urlf);
    //Initialize the delegate.

    XMLParser *parserf = [[XMLParser alloc] initXMLParser];
    [xmlParserf setDelegate:parserf];

    //Start parsing the XML file.

    BOOL successs = [xmlParserf parse];

    [UIApplication sharedApplication].networkActivityIndicatorVisible = YES;

    NSLog(@" this xml  is %d",[xmlParserf retainCount]);// getting error
    NSLog(@" this paaat is %d",[parserf retainCount]);// getting error

    if(successs)
    {
        NSLog(@"ZONE IS PARSED");
        [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
    }
    else
    {
        NSLog(@"NOT PARSED!!!");
    }

    //[xmlParserf release]; not working
            //[parserf release];
</code></pre>

<p>now i dont know when to release those objects these are running in some threads</p>
