Detect Android with PHP, Javascript & .htaccess

Android is a Linux-based operating system, designed primarily for touchscreen mobile devices such as smartphones and tablet computers. Andriod is initially developed by Android, Inc. 
While working in web technology environment, many times we came accross the situation where we need to detect that if it is Android is not. This detection can be done in multiple ways like: 
1. Using PHP 
2. Using Javascript 
3. Using .htaccess 
It totally depends on the interest of developer, which mechnaism he/she choose to detect android.

Remove optgroup from selectbox

HTML optgroup element creates a grouping of options within a select  element in web page. You might be working on optgroup in select box. Here is the simple script for the addition and deletion of optgroups. 

Prevent Grey box from hiding drop down

Today I was working with Grey box component and every thing was going smooth... But suddenly I came to know that select box on parent page become invisible as the Grey box popup comes up.