Introduction
A hit counter in flash is not hard at all. The only things required for making a hit counter in flash is a computer, Flash (preferably MX or higher), text editor (even notepad will do, I use Dreamweaver), and most importantly a server that supports php 3 or higher.

What we're going to do is draw the appearance of the counter in flash, write a php script that will store the visitor count in a small text file, and then call the php script from flash. There are two types of flash hit counters: a simple counter that increases after refreshing the page or a live counter which refreshes itself after a period of time.

[ A simple live flash hit counter using php ]

Creating the Flash Movie
We just have to make a movie with a simple textbox in it with a variable name of "count" and add some actions to make it work.

1. First open up flash, draw a new dynamic textfield onto the stage and change it's variable name to "count" (without the double-quotes).

[ dynamic textfield, var-named "count" ]

2. Now you have to decide whether you want to make a simple boring counter or a LIVE counter that refreshes itself! In case you want to make a live counter read on, otherwise skip to step VI
    
3. Make two new keyframes on your timeline, one on frame 2 and the other for example in frame 40. What we're going to do is make the timeline play to the last keyframe and then loop back to frame 2 where it refreshes itself. The interval between the refreshes depends on your fps of the movie and the length between keyframe 2 and 3 in frames. It's wise set the interval more than 4 seconds since it has to load the text file all over again every time it refreshes itself. But it isn't a big deal because the text file is just over a few bytes.

[ keyframes in frames 1, 2 and 40]

4. Now to make it work! In frame 2 copy this action:
   
   this.loadVariables("count.txt?num="+random(999));

This loads the text file named "count.txt" every time it loops back to that frame Notice the "?num="+random(999)" part. That's a query string. More about query strings in step VI.

5. Now in keyframe 3 (frame 40) copy these actions:
   
   gotoAndPlay(2);
   
   This loops the playhead back to frame 2 (and refreshes itself).
    
6. In frame 1 copy this action:
   
   this.loadVariables("counter.php?num="+random(99));
   
   This executes the php file that we will be writing soon. This php file will increase the number of visitors as well as return the number of visitors (after increasing). And again we use a query string. That's where we use a query string to make sure that it doesn't automatically load an old php file from the browser's cache. we change the variable's value to a random number between 0 and 99 so the user has a 1 out of 99 chance of getting an old text file from the cache. This time the variety of the random number doesn't have to be so large since we don't change the php file anyway (actually you can just leave it out).

Now all you need to do is publish the movie and we'll start writing the php file. But before that we must create the text file.

Creating the Text File

Open up a text editor. Type in "count=0" (without double-quotes) and save it as "count.txt".

 Creating the PHP File

1. Open up your favorite text editor. Copy and paste the following code:

<?php $count = file_get_contents("count.txt"); $count = explode("=", $count); $count[1] = $count[1]+1; $file = fopen("count.txt", "w+"); fwrite($file, "count=".$count[1]); fclose($file); print "count=".$count[1]; ?>

2. PS! Now if you have an older version of php than 4.3.0 replace
   $count = file_get_contents("count.txt");
   with
   $file = fopen("count.txt", "r");
$count = fread($file, 10240);
fclose($file);

   This does exactly the same thing but in a more complicated way :P

Code explanation
Now I will simply explain the code...

$count = file_get_contents("count.txt");

This little piece of code simply "gets" the contents of "count.txt" and assigns it to a variable (in this case $count) as a value. [ This is the 4.3.0 version of it ]

$file = fopen("count.txt", "r");
$count = fread($file, 10240);
fclose($file);

This does the exact same thing but in a more complicated way. It first opens up the file for reading. (different opening modes here)
Then it "reads" the file. That 10240 there is just the maximum length in bytes that it will read. (I'm sure your counter will never get to that point ;) )
And the third line just closes the file.

$count = explode("=", $count);
$count[1] = $count[1]+1;

The first line splits the data from the text file into an array named $count (the same as the variable before) (more about arrays here). So that the first element in the array is just the word "count" and the second is the exact count of visitors (right now it's "0").
Since the elements in an array are counted starting from 0 (0, 1, 2, etc) we take the first element (actually the second one numbered "1") and increase the value of that number.

$file = fopen("count.txt", "w+");
fwrite($file, "count=".$count[1]);
fclose($file);

The first line opens up the file for writing and truncates its length to 0. (different opening modes here).
The second line writes the new data into the text file. in the form of
"count=" + the number.
The third line simply closes the file.

  print "count=".$count[1];

This returns the count in the form of "count=" + the number. This will automatically change the value of the textbox we created in flash because the php file is loaded into flash and the php script will give a command to change the value of "count" to the number of visitors. (count was also the variable-name of our textbox remember?)

Now probably the most important thing you have to do now is when you upload your files onto a server make sure you change the permissions of the text file to 777. This can be done with telnet, Smartftp, etc. I use Smartftp. (it's most probably found under the properties of the text file)

And you're done! Your counter should be up and running! Use the search feature at php.net to find out what exactly each function does and how it's used.
If you have any questions feel free to post them in the forum.

Syko http://lvasey.com/sykopage