Does anybody have any idea why the result of following code is different each time:

PHP Code:
<?php

srand
(152);
echo 
rand();
echo 
'<br>';

srand(152);
echo 
rand();
echo 
'<br>';

srand(152);
echo 
rand();
echo 
'<br>';

srand(152);
echo 
rand();

?>
Code:
1515441909
654160073
1204705132
711690770

213509977
902459421
1801474686
900418819

....