var myImage = getElementById.innerHTML("mainImage");
//array 0 - 3
var imageArray = ["_Image_1", "_Image_2", "_Image_3", "_Image_4"];
var imageIndex = 0;
function changeImage() {
myImage.attribute("src", imageArray[imageIndex]);
imageIndex++
if (imageIndex >= imageArray.length) {
imageIndex = 0;
}
}
setInterval(changeImage, 5000);
$("#div").addClass("highlight");