how to call a script from another script in javascript

1<script type="text/javascript" src="file1.js"></script>
2<script type="text/javascript" src="file2.js"></script>
3<script type="text/javascript">
4    alertOne( );
5</script>

1// File1.js
2function alertNumber( n ) {
3    alert( n );
4};
5// File2.js
6function alertOne( ) {
7    alertNumber( "one" );
8};
9// Inline
10alertOne( ); // No errors