Question

why does this script show empty alert box. I am trying to use php value in javascript

<script type="text/javascript">
 alert(<?php echo count($myorder) ?>); </script> 

Answer 1

Probably because you are not encapsulating the PHP output into quotes (JavaScript should give you an error on that?), and the echo statement is missing a mandatory optional semicolon.

Try

<script type="text/javascript">
 alert("<?php echo count($myorder); ?>"); </script>