How to create a macro that asks if you want to rename a sheet?

I need a msgbox with an If statement that, if yes, sheet("Comparison") will be renamed; and if no, nothing happens. The new name will be the value as the user will put into message box. I don't know exactly how to do it, but I've got this at the moment:

 MsgBox Prompt:="Keep comparison?", _
     Buttons:=vbYesNo

 If vbYes Then
    '
    Else

 End If

This may not be the best way to do it, so feel free to change it, if necessary.