[Armen]

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();