how to call a javascript function which created in other JS files

[jimmyweb]

how to call a javascript function which created in other JS files
Hi Friends,
I created 2 javascript piece. one link to target js file. one is online script. in second JavaScript, i want to call a function that created in JS files.
I got a error message and can not find list name--undifine function name which created in fristcode.js. which is wrong?
below is my codes.
Thanks for any help.
jim
*******************

<script language="javascript" type="text/javascript" SRC="http://homepage/clientview/firstcode.js">
//firstcode.js define a function list
</script>

<script language="javascript" type="text/javascript">//
function kk(){
var newList = null;
newList = new List();
alert(newList);}
</script>