автопрокрутка текста в блоках с возможностью просмотра вручную

Код:
<script>
//#############################################
//# Cкрипт из библиотеки https://shara.7fi.ru             #
//# Библиотека Javascript насчитывает         #
//# более 1500 скриптов и динамических стилей #
//# Библиотека https://shara.7fi.ru            #
//#                        #
//#############################################
//#                  https://shara.7fi.ru                 #
//#############################################



document.writeln('<style type="text/css">');
document.writeln('.gallerycontroller{width: 250px}');
document.writeln('.gallerycontent{width: 250px;height: 200px;border: 1px solid black;background-color: #DFDFFF;padding: 3px;display: block;}');
document.writeln('</style>');

var tickspeed=3000 //ticker speed in miliseconds (2../000=2 seconds)
var displaymode="auto" //displaymode ("auto" or "manual"). No need to modify as form at the bottom will control it, unless you wish to remove form.
if (document.getElementById){
document.write('<style type="text/css">\n')
document.write('.gallerycontent{display:none;}\n')
document.write('</style>\n')
}
var selectedDiv=0
var totalDivs=0
function getElementbyClass(classname){
partscollect=new Array()
var inc=0
var alltags=document.all? document.all.tags("DIV") : document.getElementsByTagName("*")
for (i=0; i<alltags.length; i++){
if (alltags[i].className==classname)
partscollect[inc++]=alltags[i]
}
}
function contractall(){
var inc=0
while (partscollect[inc]){
partscollect[inc].style.display="none"
inc++
}
}
function expandone(){
var selectedDivObj=partscollect[selectedDiv]
contractall()
selectedDivObj.style.display="block"
temp.options[selectedDiv].selected=true
selectedDiv=(selectedDiv<totalDivs-1)? selectedDiv+1 : 0
if (displaymode=="auto")
autocontrolvar=setTimeout("expandone()",tickspeed)
}
function populatemenu(){
temp=document.gallerycontrol.menu
for (m=temp.options.length-1;m>0;m--)
temp.options[m]=null
for (i=0;i<totalDivs;i++){
var thesubject=partscollect[i].getAttribute("subject")
thesubject=(thesubject=="" || thesubject==null)? "HTML Content "+(i+1) : thesubject
temp.options[i]=new Option(thesubject,"")
}
temp.options[0].selected=true
}
function manualcontrol(menuobj){
if (displaymode=="manual"){
selectedDiv=menuobj
expandone()
}
}
function preparemode(themode){
displaymode=themode
if (typeof autocontrolvar!="undefined")
clearTimeout(autocontrolvar)
if (themode=="auto"){
document.gallerycontrol.menu.disabled=true
autocontrolvar=setTimeout("expandone()",tickspeed)
}
else
document.gallerycontrol.menu.disabled=false
}
function startgallery(){
document.getElementById("controldiv").style.display="block"
getElementbyClass("gallerycontent")
totalDivs=partscollect.length
populatemenu()
for (i=0; i<document.gallerycontrol.mode.length; i++){
if (document.gallerycontrol.mode[i].checked)
displaymode=document.gallerycontrol.mode[i].value
}
if (displaymode=="auto")
document.gallerycontrol.menu.disabled=true
expandone()
}
if (window.addEventListener)
window.addEventListener("load", startgallery, false)
else if (window.attachEvent)
window.attachEvent("onload", startgallery)
else if (document.getElementById)
window.onload=startgallery
document.writeln('<div class="gallerycontent" subject="Первая строка">Это первый текст</div>');
document.writeln('<div class="gallerycontent" subject="Вторая строка">Это второй текст</div>');
document.writeln('<div class="gallerycontent" subject="Третья строка">Это третий текст</div>');
document.writeln('<div id="controldiv" style="display:none" class="gallerycontroller">');
document.writeln('<form name="gallerycontrol">');
document.writeln('<select class="gallerycontroller" size="3" name="menu" onChange="manualcontrol(this.options.selectedIndex)">');
document.writeln('<option>Blank form</option>');
document.writeln('</select><br>');
document.writeln('Auto: <input type="radio" checked name="mode" value="auto" onClick="preparemode(\'auto\')"> Manual: <input type="radio" name="mode" value="manual" onClick="preparemode(\'manual\')">');
document.writeln('</form>');
document.writeln('</div>');
</script>