What is the difference between an Else followed by an If-EndIf and the If-ElseIf-EndIf structure?
Nothing. The two procedures given below are identical in functionality. If the logic of your program is amenable to using ElseIf and there are more than a couple of nested conditions, use ElseIf. In such cases, using Else followed by If will make your program slither away into the Land of the Unreadable Code.