extenal javascript

[lolodede]

i have external javascript

var titles = new Array();
        titles[0] = "Mr";
        titles[1] = "Mrs";
        titles[2] = "Miss";
        titles[3] = "Ms";
	titles[4] = "Dr";

var courseNum = new Array();       //this array is in parallel with the courseName array.
        courseNum[0] = "3503";
        courseNum[1] = "3508";
        courseNum[2] = "3633";
        courseNum[3] = "3639";
        courseNum[4] = "7005";
	courseNum[5] = "1624";

var courseName = new Array();          //this array is in parallel with the courseNum array.
        courseName[0] = "Bachelor of Industrial Design";
        courseName[1] = "Bachelor of Information Technology";
        courseName[2] = "Bachelor of Computing";
        courseName[3] = "Bachelor of Information and Communications Technology";
        courseName[4] = "Diploma in Information and Communications Technology";
	courseName[5] = "Bachelor of Design Studies";

saves as assignone.js
i want to put titles into select like html read it from external to put it into select
same thing for others but i want to when the user select one of the course numbers automaticaly appear the course name
thanks