Random image
Ever wanted to know how to create the random gallery ? The same gallery as you can see on webclass.ru pages.
Well, here is the way you can do it:
<?php
$imgpath = "path/to/image/dir";
$handle = opendir( "$imgpath" );
$imgArray = array();
while($file = readdir($handle))
{
    if( $file != "." && $file != ".." )
    {
        array_push( $imgArray, $file );
    }
}
closedir( $handle );
mt_srand( (double)microtime( ) * 1000000 );
$randval = mt_rand( 0, sizeof( $imgArray ) - 1 );
print( "<IMG SRC=\"$imgpath/" . $imgArray[ $randval ] . "\">" );
?>

Is it complicated ? Then let's comment the code.

$handle = opendir( "path/to/image/dir" );
$imgArray = array();

Opens the folder where the images are stored and then empties the array of images.

while($file = readdir($handle ))
{
    if($file != "." && $file != "..")
    {
        array_push( $imgArray, $file );
    }
}
closedir( $handle );

The code above starts a loop, reads folder contents and checks if the file is not a folder. Then a name of the file is stored in the array and folder is closed when the cycle is over.

$randval = mt_rand( 0, sizeof( $imgArray ) - 1 );

This line generates a random value not greater than number of files in the directory.

print( "<IMG SRC=\"img/" . $imgArray[ $randval ] . "\">" );

Last step is to print image tag code to the page.