如何在div中更改边框颜色？

I am new to web development, i have learned basics of Java, JSP, HTML, JS, CSS, JQ. I am stuck at a point in which I am trying to change the border color of a div when mouse hover event occurs, but I am failing in doing so. Below is the related code, please point out the mistakes and point me in a better directions. Thanks alot in advance.I am new to web development, i have learned bas