Help with retrieving data from database syntax

[Pete1980]

basically Im building a sales site that when you place an order it inputs it into a data base.
I have made an admin page that views the orders in a grid view with the select option enabled.
The problem im having is that I want to select the username from the orders then display in a text box the users address.

This is the code I have

 Protected Sub GridView1_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs)

        Dim txtUserName As String
        Dim strGet As String
        
        txtUserName = GridView1.SelectedRow.Cells(3).Text()
        strGet = "select * from Security WHERE LogonId = '" & txtUserName & "'"
                
        txtUser.Text = strGet
        
    End Sub

I am thinking the problem is in this line

strGet = "select * from Security WHERE LogonId = '" & txtUserName & "'"

Please help, im going nuts!!

[Pete1980]

After countless hours and lots of head bashing Problem solved!!
I had to add

onselectedindexchanged="GridView1_SelectedIndexChanged"

to the gridview
and use

Dim daValidate As New OleDbDataAdapter(strGet, Conn)
        Dim dsValidate As New DataSet()
        
        daValidate.Fill(dsValidate, "dsItems")
        
        intRowNumber = 0
        
        Try
            txtUserDetails.Text = "User Name: " & dsValidate.Tables("dsItems").Rows(intRowNumber).Item("LogonId") & ControlChars.NewLine & "Name: " & dsValidate.Tables("dsItems").Rows(intRowNumber).Item("firstName") & " " & dsValidate.Tables("dsItems").Rows(intRowNumber).Item("lastName") & ControlChars.NewLine & "Address " & dsValidate.Tables("dsItems").Rows(intRowNumber).Item("houseNum") & " " & dsValidate.Tables("dsItems").Rows(intRowNumber).Item("streetName") & " " & dsValidate.Tables("dsItems").Rows(intRowNumber).Item("suburb") & " " & dsValidate.Tables("dsItems").Rows(intRowNumber).Item("state") & " " & dsValidate.Tables("dsItems").Rows(intRowNumber).Item("postCode") & ControlChars.NewLine & "Email: " & dsValidate.Tables("dsItems").Rows(intRowNumber).Item("email")

Just in case anyone cared.. lol