NEED HELP WITH A BUG

my error says "handles clause requires a withevents variable defined in the containing type or one of its base types" whenevr i try to input this code and idk hwo to fix Public Class frmConcatenationText Private Sub btnSubmit_Click(sender As Object, e As EventArgs) Handles btnSubmit.Click ' Concatenate the strings Dim strResult As String = "Hello" & "World" & "!" ' Display the result on a pop-up message box MsgBox(strResult) End Sub End Class and also Public Class frmConcatenationText Private Sub BtnTest_Click(sender As Object, e As EventArgs) Handles btnTest.Click Dim strResult As String 'Declare a variable to hold result of concatenated strings Dim strValue1 As String = "Hello" Dim StrValue2 As String = "World!" strResult = strValue1 & StrValue2 'Combine the strings strValue1 and strValue2 MsgBox(strResult) 'Display the result on a pop-up message box End Sub End Class ( they do the same thing but that one bug is the only problem )