function jQuery(e) {
    return document.getElementById(e);
}

document.getElementsByClassName = function(cl) {
    var retnode = [];
    var myclass = new RegExp("\\b" + cl + "\\b");
    var elem = this.getElementsByTagName("*");
    for (var i = 0; i < elem.length; i++) {
        var classes = elem[i].className;
        if (myclass.test(classes)) retnode.push(elem[i]);
    }
    return retnode;
};

var MyMar;

var speed = 1;

//速度，越大越慢
var spec = 1;

//每次滚动的间距, 越大滚动越快
var ipath = "../../jq22images/";

//图片路径
var thumbs = document.getElementsByClassName("thumb_img");

for (var i = 0; i < thumbs.length; i++) {
    thumbs[i].onmouseover = function() {
        jQuery("main_img").src = this.rel;
        jQuery("main_img").link = this.link;
    };
    thumbs[i].onclick = function() {
        location = this.link;
    };
}

jQuery("main_img").onclick = function() {
    location = this.link;
};

jQuery("gotop").onmouseover = function() {
    this.src = ipath + "gotop2.gif";
    MyMar = setInterval(gotop, speed);
};

jQuery("gotop").onmouseout = function() {
    this.src = ipath + "gotop.gif";
    clearInterval(MyMar);
};

jQuery("gobottom").onmouseover = function() {
    this.src = ipath + "gobottom2.gif";
    MyMar = setInterval(gobottom, speed);
};

jQuery("gobottom").onmouseout = function() {
    this.src = ipath + "gobottom.gif";
    clearInterval(MyMar);
};

function gotop() {
    jQuery("showArea").scrollTop -= spec;
}

function gobottom() {
    jQuery("showArea").scrollTop += spec;
}