Здравсвуйте, подскажите пожалуйста, почему alert в цикле for не отрабатывает.
<ul id="lists-r1">
<li class="list-r1">Alcohol And Drugs</li>
<li class="list-r1">Becoming Familiar With Your Vehicle</li>
<li class="list-r1">Defensive Driving Techniques</li>
<li class="list-r1">Driving In Bad Weather</li>
<li class="list-r1">Driving Privileges</li>
<li class="list-r1">Laws And Rules Of The Road</li>
<li class="list-r1">Road Rage</li>
<li class="list-r1">Seat Belts</li>
<li class="list-r1">Sharing The Road</li>
<li class="list-r1">Signs, Signals, and Markings</li>
<li class="list-r1">Space Management</li>
</ul>
function getPlay(_timeDelay, _timeSpeed, _timeOpacity)
{
this.timeDelay = _timeDelay;
this.timeSpeed = _timeSpeed;
this.timeOpacity = _timeOpacity;
this.arrCoords = [1,2];
};
getPlay.prototype.getPosition = function()
{
this.li = document.getElementsByClassName('list-r1');
for(var i = 0; i <= this.li; i ++)
{
alert("1")
}
};
var obj = new getPlay(10, 20, 30);
obj.getPosition();