Not implement error

[anandedward]

hi
i have face the problem in javascript "Not implement error" these error will be occur follwing coe and pointout the line wher the probelm occur, and how solve these problem

var ajax = new Object();
ajax = false;

var tl = new Array("....","....","....","....","....");
var count=0;
var x = 0;
var pos = 0;
var l = tl[0].length;
//alert(l);
var timerid;


				function startProgress(){
					  
					  ajax = true;	 
					  
					  window.onload=textticker();   //"Not implemented error occur here only "
					  showProgress();	
					  
					  
					} 
				
				function showProgress() { 	
					if(ajax == true){ 
					textticker();
					
					} 		
				}
				function GetIndex1() {
							if(count==5){
							//alert("1");
							count=0;
							return 0;
								}
							else {
							//alert("2");
							return count++;
								}
								}
				
				
				function textticker() 
				{
				
					
					var obj=document.getElementById("loadingDiv");
					
					obj.innerText="Please Wait"+tl[GetIndex1()].substring(0, pos);
				
					//alert(pos++);
					if(pos++ == l) {
						pos = 0;
						timerid=setTimeout("textticker()", 200);
						//alert(++x);
						
						} 
						else{
						timerid=setTimeout("textticker()", 500);
						}
				
				}
				
				
				function haltCounter() 
					{
				   clearTimeout(timerid);
				
					}
	document.onstop = haltCounter;