The actors are encouraging children between the ages of six and 14 to treat each other with respect online.

The crusaders are also urging parents to monitor their kids' use of cell phones, social networking and gaming sites.

Lab Rats star Unger, 16, has drawn on his own experience to help promote the movement - he was taunted with names such as ""small fry"" and ""shortie"" in his early school days.

The actor was given the boost he needed to stand up to bullies after a casting agent informed him a shorter height was advantageous for a child entering the entertainment industry.

In a statement, he said, ""So from that point on, when people called me small fry or shortie I was like: ""Yeah, you're right and I am proud of it.""