Timeout error while executing delete query in SqlCommand

[winman]

Hi,

We have a Vb.net program and we are using SqlCommand to execute some queries.This is the code block

If Trim(Slno) <> "" Then
                    oCmd_Local = New SqlCommand("select * from ErrorReport_analysis where (sl_no = '" & Slno & "' and Product = '" & ProductStr & "') order by id", Connum_Local)
                    rs_local = oCmd_Local.ExecuteReader
                    If rs_local.Read = True Then

                        If Trim(Hostname) <> "" Then
                            oCmd_Local = New SqlCommand("select count(*) from ErrorReport_analysis where (sl_no = '" & Slno & "' and Product = '" & ProductStr & "' and HOSTNAME = '" & Hostname & "')", Connum_Local2)
                            rs_local2 = Val(oCmd_Local.ExecuteScalar.ToString)
                        ElseIf Trim(CompKey) <> "" Then
                            oCmd_Local = New SqlCommand("select count(*) from ErrorReport_analysis where (sl_no = '" & Slno & "' and Product = '" & ProductStr & "' and PC_key like '%-" & CompKey & "-%')", Connum_Local2)
                            rs_local2 = Val(oCmd_Local.ExecuteScalar.ToString)
                        End If

                        If rs_local2 = 1 Then 'if only one row present then delete that row itself
                            oCmd_Local = New SqlCommand("Delete from ErrorReport_analysis where (id = " & rs_local.Item("id").ToString & ")", Connum_Local2)
                            oCmd_Local.CommandTimeout = TimeOutval
                            oCmd_Local.ExecuteNonQuery()
                        Else
                            Do While rs_local.Read = True
                                If Trim(Hostname) <> "" Then
                                    If rs_local.Item("HOSTNAME").ToString = Hostname Then
                                        oCmd_Local = New SqlCommand("Delete from ErrorReport_analysis where (id = " & rs_local.Item("id").ToString & ")", Connum_Local2)
                                        oCmd_Local.CommandTimeout = TimeOutval
                                        oCmd_Local.ExecuteNonQuery()
                                        Exit Do
                                    End If
                                ElseIf Trim(CompKey) <> "" Then
                                    If InStr(rs_local.Item("PC_key").ToString, "'%-" & CompKey & "-%'", CompareMethod.Text) > 0 Then
                                        oCmd_Local = New SqlCommand("Delete from ErrorReport_analysis where (id = " & rs_local.Item("id").ToString & ")", Connum_Local2)
                                        oCmd_Local.CommandTimeout = TimeOutval
                                        oCmd_Local.ExecuteNonQuery()
                                        Exit Do
                                    End If
                                Else
                                    Exit Do
                                End If
                            Loop
                        End If
                    End If
                    rs_local.Close()
                    rs_local = Nothing
                Else
                    oCmd_Local = New SqlCommand("select * from ErrorReport_analysis where ((sl_no ='' or sl_no is null) and PC_key like '%-" & CompKey & "-%' and HOSTNAME = '" & Hostname & "' and Product = '" & ProductStr & "') order by id", Connum_Local)
                    rs_local = oCmd_Local.ExecuteReader
                    If rs_local.Read = True Then
                        oCmd_Local = New SqlCommand("Delete from ErrorReport_analysis where (id = " & rs_local.Item("id").ToString & ")", Connum_Local2)
                        oCmd_Local.CommandTimeout = TimeOutval
                        oCmd_Local.ExecuteNonQuery()
                    End If
                    rs_local.Close()

                    rs_local = Nothing
                End If

            End If

But while executing delete statement some this timeout error coming

I have Executed sp_who2 command in Management studio and find out that there are 4 sessions created by program and a session with select statement is blocking the session with delete statement.Why this is happening?what to do?

Thank you