I'm getting the following error
BC30408: Method 'Public Function GetSalesman() As Object' does not have the same signature as delegate 'Delegate Sub EventHandler(sender As Object, e As System.EventArgs)'.

Are you using Addhandler somewhere?

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I will only tell you how to do it, not do it for you.
Unless, of course, you want to hire me to do work for you.

^^Thats my signature

No, What is that?

On your front end do this:

<asp:Label id=lbl2 runat=server />

On your backend do this:
Private Sub Page_Load(ByVal sender as Object, ByVal e as EventArgs)
If not Page.IsPostBack
     lbl2.Text = GetSalesman()
End If
End Sub

Ill explain Addhandler after we deal with this problem.

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I will only tell you how to do it, not do it for you.
Unless, of course, you want to hire me to do work for you.

^^Thats my signature

Now I'm getting
System.InvalidCastException: Cast from type 'DataSet' to type 'String' is not valid

....so change the signature of your function to [function declaration] as string and return a value from your dataset.

-------------------------
I will only tell you how to do it, not do it for you.
Unless, of course, you want to hire me to do work for you.

^^Thats my signature

Something like this:

Function GetSalesman (ByVal FieldName As String) As String

End Function

Yes

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I will only tell you how to do it, not do it for you.
Unless, of course, you want to hire me to do work for you.

^^Thats my signature

I'm getting:

BC30311: Value of type 'System.Data.DataSet' cannot be converted to 'String'


Dim a As String
Sub Page_Load(sender As Object, e As EventArgs)
      If not Page.IsPostBack
          a = Context.User.Identity.Name
         lbl2.Text = GetVendedor(a)
      End If
End Sub

Function GetVendedor (ByVal FieldName As String) As String
//some code
End Function

You cannot just return your dataset as I imagine you are doing something like this:

Return ds

That is why you are getting the error. You have to access your Dataset, then the datatable contained inside the dataset, and then retrieve the value that you want to work with.

ds.Tables[0].Rows[0].Item["columnname"]

-------------------------
I will only tell you how to do it, not do it for you.
Unless, of course, you want to hire me to do work for you.

^^Thats my signature