readyState is null or not an object error

[krishnagovindaraj]

Hi All,


I have to display the value in textbox that is selected from dropdownlistbox using ajax.i got the readyState is null or not an object error.

coding:

 <script language="javascript" type="text/javascript">
 function GetDataViaAJAX()
{
var obj;
try
{
obj = new ActiveXObject("Msxml2.XMLHTTP");
}
catch(e)
{
try
{
obj = new ActiveXObject("Microsoft.XMLHTTP");
}
catch(e1)
{
obj = null;
}
}
if(obj!=null)
{
obj.onreadystatechange=stateChanged;
obj.open("GET","ajaxex.aspx?client="+ document.getElementById("DropDownList1").value,true);
obj.send(null);        
}
return false;
}
 
function stateChanged() 
{ 
var obj;
if (obj.readyState == 4)
{ 
var textclient=obj.responseText;
alert(textclient);
var textclientobj=document.getElementById("TextBox1");
textclientobj.innerHTML=textclient;
 
}
}
</script>
 

ajaximp.aspx.cs:

protected void Page_Load(object sender, EventArgs e)
    {
 
        DropDownList1.Attributes.Add("onChange", "return GetDataViaAJAX();");
        }     

Plz give me a solution.its urgent!!!!

Thaks
Krish

[kenobewan]

Here is an article that may help:
AJAX for ASP.NET

[aneesahamed]

Hello krishnagovindaraj,

I know it is too late reply. Since just now I come across your question and thought of helping you. To avoid your issue remove variable declaration for "obj" from onstate function and check.

[Plater]

Well this was a really simple answer, not sure why its being brought up
Of course readyState doesn't exist, obj is a null object in this instance

var obj; 
if (obj.readyState == 4) 
{  
 

Remove the var obj; line and it should be fine