Reply To: PHP contact form not showing error color

[etoilethay]

Thanks traq:
Here is the code
http://pastebin.com/mZZWuJbj

The form is designed in away that if the input is not valid and after clicking the submit button, the input box with error should have a red border rather than black.
In my case the border color stays black and hence the user will not know what input is supposed to be corrected.