Question: I received the following error:

```
[27-Apr-2009 10:26:06] PHP Fatal error:  Cannot redeclare alphanumeric() (previously declared in /home/iddoc/public_html/lib/common.php:6) in /home/iddoc/public_html/lib/common.php on line 8

```

Notice this:

```
/home/iddoc/public_html/lib/common.php:6) in 
/home/iddoc/public_html/lib/common.php on line 8

```

Here are the offending lines:

```
function alphanumeric($str) {
    return strtolower(preg_replace("/[^A-Za-z0-9]/",'',$str));
}

```

Prior to these lines there are only comments. There is no other declaration of that function anywhere else in that file or any other.

Strange, no?

Answer: 
Are you using require\_once() to include common.php everywhere? If you use just require or include, that will cause this issue.
Sounds like you've got the common.php file included more than once. Do you use include(), require() or require\_once() for your includes?