Chào các bạn, hiện nay bên forum chủ ở nước ngoài đã trả lời cho mình cách làm, anh Admin chỉnh các thông số trong bảng điều khiển dùm em nha :
Enabling HTML
In order to have HTML applications (such as flash games, images, and other sources) in users' posts, you'll have to activate HTML in both the Administration Panel and the user's profile :
Enabling HTML via Administration Panel
Administration Panel >
General tab >
Forum -- Messages and Emails >
While in the Messages section on this page, scroll down a wee bit to where the statement Allow HTML : is keyed, and select Yes next to it.
Be sure that you Save the settings afterwards.
Enabling HTML via Profile
Profile tab (found on Navigation Bar); or My Profile (found on the Log-In widget) >
Preferences tab >
From that page, scroll down a bit to where Always allow HTML : is keyed on the page, and select Yes next to it.
Be sure that you Save the settings afterwards.
Also, there is a high recommendation for you to have an Announcement in your forum discussing how users can enable HTML.
Written by Rok