[GTLS]

The thing is, != sign (Exclamation mark followed by an equals), means Not Equal to. while double equal means equal too. You used double equal to in your code that is why it got reverted. As Mughla did, he combined both lines using && sign (double ampersand ) which means AND relation. Mughla had not provided explanation so I thought I'd give it for people who are new to programming.