var course1 = new Image();
var course2 = new Image();
var course3 = new Image();
var course4 = new Image();
var course5 = new Image();
var course6 = new Image();
var course7 = new Image();
var course8 = new Image();
var course9 = new Image();
var course10 = new Image();


course1.src = "images/course_1.jpg";
course2.src = "images/course_2.jpg";
course3.src = "images/course_3.jpg";
course4.src = "images/course_4.jpg";
course5.src = "images/course_5.jpg";
course6.src = "images/course_6.jpg";
course7.src = "images/course_7.jpg";
course8.src = "images/course_8.jpg";
course9.src = "images/course_9.jpg";
course10.src = "images/course_10.jpg";

function doButtons(picimage) {
eval("document['picture'].src = " + picimage + ".src");
}