You just use an if statement to determine the msgbox return is "Yes" (vbTure) or "No" (vbNo) on the line. If it is "Yes", don't worry about it, the code will be automatically executed down, if it is "No" on the End, the code is as follows:

If MsgBox("Is it executed?"), 4 + 32, "Prompt", "Is it executed?"), 4 + 32, "Is it executed?", 4 + 32, "Is it executed?"), 4 + 32, "Prompt", "Is it executed? , 4 + 32, "Prompt") = vbNo Then

End

End If