Login Failed For 'servername/aspnet'

hi,

I am very new to asp.net..I am creating a webform which connects to sqlserver and  display table contents  to a grid control.When i run this form,i get error message as follows
Login failed for user 'SERVERNAME/ASPNET'.

I have read in one page of this forum that we should create aspnet user in sqlserver..i tried to create user,i can see 2 user Guest and public...I don't know what to do ?

If  someone replies my question,i would appreciate..I have struggling with this for the past 1 week..i couldn't find a solution.

My code  is as follows:

Dim MyConnection As SqlClient.SqlConnection

Dim MyCommand As SqlClient.SqlDataAdapter

Response.Write("hello world")

MyConnection = New SqlClient.SqlConnection("server=Localhost;Integrated Security=SSPI;uid=sa;password=;database=sample")

MyCommand = New SqlClient.SqlDataAdapter("select * from emp", MyConnection)

Dim ds = New DataSet

MyCommand.Fill(ds, "emp")

Response.Write("data set has been created")

DataGrid1.DataSource = ds.Tables("emp").DefaultView

DataGrid1.DataBind()

 thanks

kar