I'm trying to make my email validation do exactly this

```
combination of letters (both upper & lower case), numbers and periods
single at symbol @ 
combination of letters (both upper & lower case), numbers, hyphens and/or periods
single period
combination of 2 – 4 letters (lower case only)

```

This is what I have and please correct me if I am wrong.

JSFIDDLE: <http://jsfiddle.net/uk6cD/3/>