Problem with External Interface

1

i want to call a javascript function from within an embeded swf file in a html page and i’m using the ExternalInterface class. i know this function must be defined in a <script> tag in the html page. however, i want to have all my javascript code in an external file, but it doesn’t work. my trial file just can’t find the function, although i have my external js file linked in the header. how can i do this? i’d really appreciate your help, thanks.