I'm working on a site that will make it responsive. Media queries are working on the device it self but on browser resize it's not taking effect. This is my code. Did I missed something? Thanks in advance!

```
@media only screen and (min-device-width : 320px) and (max-device-width :     
480px) and (orientation: portrait) {

  //Code Here

}

@media only screen and (min-device-width : 320px) and (max-device-width :  
480px) and (orientation: landscape) {

  //Code Here

}

```