variable "stat_in" is used before it has been assigned a value. a null exception could result at runtime

                If timeCounter = 1 And stat = "ACTIVE" Then
                    stat_in = "IN"
                    Using SQLConnection As New MySqlConnection(ServerString)
                        Using command As New MySqlCommand()
                            With command
                                .CommandText = "INSERT into time_table(id,student_id,tag,date,time,status) VALUES(@id,@student_id,@tag,@date,@time,@status); UPDATE rfid_stud SET timeCounter = 2 WHERE tag = '" & txtReceived.Text & "'"
                                .Connection = SQLConnection
                                .CommandType = CommandType.Text
                                .Parameters.AddWithValue("@id", idnum)
                                .Parameters.AddWithValue("@student_id", txtStudNo.Text)
                                .Parameters.AddWithValue("@tag", txtReceived.Text)
                                .Parameters.AddWithValue("@date", txtDate.Text)
                                .Parameters.AddWithValue("@time", txtTime.Text)
                                .Parameters.AddWithValue("@status", stat_in)
                            End With
                            Try
                                SQLConnection.Open()
                                command.ExecuteNonQuery()
                            Catch ex As Exception
                            Finally
                                SQLConnection.Close()
                            End Try
                        End Using
                    End Using
                ElseIf timeCounter > 1 And stat = "ACTIVE" Then
                    stat_in = "OUT"
                    Using SQLConnection As New MySqlConnection(ServerString)
                        Using command As New MySqlCommand()
                            With command
                                .CommandText = "INSERT into time_table(id,student_id,tag,date,time,status) VALUES(@id,@student_id,@tag,@date,@time,@status); UPDATE rfid_stud SET timeCounter = 1 WHERE tag = '" & txtReceived.Text & "'"
                                .Connection = SQLConnection
                                .CommandType = CommandType.Text
                                .Parameters.AddWithValue("@id", idnum)
                                .Parameters.AddWithValue("@student_id", txtStudNo.Text)
                                .Parameters.AddWithValue("@tag", txtReceived.Text)
                                .Parameters.AddWithValue("@date", txtDate.Text)
                                .Parameters.AddWithValue("@time", txtTime.Text)
                                .Parameters.AddWithValue("@status", stat_in)
                            End With
                            Try
                                SQLConnection.Open()
                                command.ExecuteNonQuery()
                            Catch ex As Exception
                            Finally
                                SQLConnection.Close()
                            End Try

                        End Using
                    End Using
                Else
                    MsgBox("RFID Card is INACTIVE! Please Contact System Administrator for assisstance.", vbExclamation, "Warning!")
                End If

                For i = 0 To (grid.Rows.Count - 1)
                    stringfix = grid.Rows.Item(i).Cells(0).Value
                    string1 = Microsoft.VisualBasic.Mid(stringfix, 1, 12)
                    string2 = Microsoft.VisualBasic.Mid(stringfix, 2, 12)
                    If string1 = string2 Then
                        newtag = False
                        Exit For
                    Else
                        newtag = True
                    End If
                Next
                If newtag = True And stat = "ACTIVE" Then
                    Dim dr As Integer
                    dr = grid.Rows.Add()
                    grid.Rows.Item(dr).Cells.Item(0).Value = txtReceived.Text
                    grid.Rows.Item(dr).Cells(1).Value = txtStudNo.Text
                    grid.Rows.Item(dr).Cells(2).Value = txtFname.Text
                    grid.Rows.Item(dr).Cells(3).Value = txtLname.Text
                    grid.Rows.Item(dr).Cells.Item(4).Value = txtDate.Text + " at " + txtTime.Text


                    If stat_in = "IN" Then
                        grid.Rows.Item(dr).Cells(5).Style.BackColor = Color.Green
                        grid.Rows.Item(dr).Cells(5).Style.ForeColor = Color.White
                        grid.Rows.Item(dr).Cells.Item(5).Value = stat_in
                    ElseIf stat_in = "OUT" Then
                        grid.Rows.Item(dr).Cells(5).Style.BackColor = Color.Red
                        grid.Rows.Item(dr).Cells(5).Style.ForeColor = Color.White
                        grid.Rows.Item(dr).Cells.Item(5).Value = stat_in
                    End If

                End If

I have a warning on "If stat_in = IN". The main warning is the "stat_in" The same code runs on my pc without warning, but when I transfer my system to my laptop it shows 2 warnings. The program runs on my pc perfectly. Warnings are Warning BC42104 Variable 'stat_in' is used before it has been assigned a value. A null reference exception could result at runtime and the other one is variable "stat_in" is used before it has been assigned a value. a null exception could result at runtime. Desktop = windows 10, Laptop = windows, 7. I also tried it on a windows 10 laptop. Its not working too. Same version of Visual Studio. Visual Studio 2015 community. Im thinking of frameworks? Please help me. Im a beginner in coding vb.net.