enable javascript and other HTML element in wordpress MU. open wp-includes/kses.php find following line

$allowedposttags = array(

add following codes

		'script' => array(
'type' => array(),
'src' => array(),
'language' => array()
),
'noscript' => array(
),
'object' => array(
'height' => array(),
'width' => array(),
'type' => array(),
'data' => array(),
'allowfullscreen' => array(),
'id' => array()
),
'param' => array(
'name' => array(),
'value' => array()
),
'embed' => array(
'width' => array(),
'height' => array(),
'type' => array(),
'src' => array(),
'allowfullscreen' => array()
),
'coolcode' => array(
'lang' => array()
),
//over