window.onload = setPictures;

function setPictures() {
    var img = document.getElementsByClassName('image');
    for (var i=0; i<img.length; i++) {
        img[i].onmouseover = function() {
                this.src = mouseOn.jpg;
                this.style.opacity = .7;}
    }
}

function setPictures() {
    var img = document.getElementsByClassName('image');
    var desc = document.getElementsByClassName('description');
    for (var i=0; i<img.length; i++) {
        img[i].onmouseover = function() {
                this.src = mouseOn.jpg;
                this.style.opacity = .7;
                disc[i].style.borderColor="#0e3e09";}
    }
}

disc[1].style.borderColor="#0e3e09";
disc[2].style.borderColor="#0e3e09";