I have developed a wordpress plugin named “devlifoiFrame” for enable iFrame at wordpress posts. This is very simple and easy to use and customizable.
Download: If you want to download this, just comment me, i will send you the download link. This plugin is free.
Upload: Upload this devlifoiFrame.php to [wordpress_dir]/wp-content/plugins/
Activation: Go to your wordpress admin panel and then to the menu item “Plugins”. In this page you can see a list of plugins. Select the plugin with named “lifoiFrame” then click on right side “Activate” link.
Use: To use this plugin i mean to add iFrame to you post, you need to a single line to your post where you want to add iFrame.
The syntex: [devlifoiFrame web_address width height]
Example: [devlifoiFrame http://www.devlifo.wordpress.com 450 400]
Input Screen Shots: gray circle is the plugin syntex to add iFrame.
Output Screen Shots: gray circle is the plugin Outpur.
Posted by lifos 
