Object reference not set to an instance of an object

HERE'S MY SCRIPT;

<%@dotnet.itags.org. Page Language="VB" Debug="True" CodePage="28599" %>
<%@dotnet.itags.org. Import NameSpace="System.Data" %>
<script runat="server">
Sub Page_Load(Obj As Object,E As EventArgs)
'DataSet Nesnesini Olustur -------
Dim ds as new DataSet("ornek_dataset")
'Tablo Olustur-----------
Dim musteritable as New DataTable("müsteriler")
'Tabloya Sutunlar Ekle--------
musteritable.Columns.Add ("ad",System.Type.GetType("System.String"))
musteritable.Columns.Add ("soyad",System.Type.GetType("System.String"))
musteritable.Columns.Add ("meslek",System.Type.GetType("System.String"))
musteritable.Columns.Add ("yas",System.Type.GetType("System.Int32"))
'Tabloyu DataSete Ekle --------
ds.Tables.Add(musteritable)
'Satir Olusturup, Veri Gir-------
Dim sira As DataRow = musteritable.NewRow
sira("ad")="Zafer"
sira("soyad")="Demirkol"
sira("meslek")="Web Programcýsý"
sira("yas")="33"
musteritable.rows.Add(sira)

Dim sira1 As DataRow = musteritable.NewRow
sira("ad")="Serdar"
sira("soyad")="Benli"
sira("meslek")="Pazarlamacý"
sira("yas")="32"
musteritable.rows.Add(sira1)

Dim sira2 As DataRow = musteritable.NewRow
sira("ad")="Denizhan"
sira("soyad")="Akkaya"
sira("meslek")="Muhasebeci"
sira("yas")="26"
musteritable.rows.Add(sira2)

Dim sira3 As DataRow = musteritable.NewRow
sira("ad")="Levent"
sira("soyad")="Demirkol"
sira("meslek")="Aþcý"
sira("yas")="28"
musteritable.rows.Add(sira3)
'----~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-----
Response.Write(ds.Tables("musteriler").rows(2)("ad") & "<br>")

Dim satir_3 As Datarow
satir_3 = ds.Tables("musteriler").rows(2)
Response.Write(satir_3(0) & "<br>")

Dim siralar As DataRowCollection
siralar=ds.Tables("musteriler").rows
Response.Write(siralar(2)("ad") & "<br>")

Dim tablo_degiskenim As DataTable
tablo_degiskenim = ds.Tables("musteriler")
Response.Write(tablo_degiskenim.rows(2)(0) & "<br>")

End sub
</script
AND THE ERROR PAGE;

Object reference not set to an instance of an object.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error:

Line 43: musteritable.rows.Add(sira3)
Line 44: '----~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-----
Line 45: Response.Write(ds.Tables("musteriler").rows(2)("ad") & "<br>")
Line 46:
Line 47: Dim satir_3 As Datarow

Source File: D:\ASP.NET\dataset_olustur2.aspx Line: 45

I COULDN'T SEE THE MISTAKE, CAN YOU HELP ME?
THANX ...When you created the table, you called it "müsteriler".

Then, when you referenced it on Line 45, you called it "musteriler" ... with no accent ...
Oh yeah ! :)
...

I am bad at my native-lang "Turkish" just like I am bad at English ...
ü is a fuckin' letter in our keyboards ...

...

Thanx NewKid2 ...
If you find this happening too often, considerchanging the language of your computer.