I usually create an EndIf Straight away and then put the code inside. For instance, I'd type:
If Num > 150
EndIf `Num > 150
Then go in and put the code or more if's:
If Num > 150
If Num < 200
EndIf `Num < 200
EndIf `Num > 150
Doing that I usually never forget an EndIf because you put it in straight away. It's also good to comment the EndIf's if you have lots nested or near eachother like above.
That's just my style though and a suggestion if you have lots of problems - it's something I brought over from VB which is why my only problem with If Statements is sometimes I type "End If" with a space.
"Computers are useless they can only give you answers."