1. Viewing a promotion video and a demonstration video: Through the webpage, they will access an online video of about seven minutes in length promoting HIVST-online. The video had been used effectively in the previous HMRF HIVST-online project. The carefully design contents were guided by Health Belief Model. For instance, health communication messages are presented to increase viewers' perceived susceptibility of HIV infection and perceived benefit of HIVST-online. As the Social Cognitive Theory suggests that observational learning is effective in inducing health-related behaviors, the video also includes short testimonials about good experiences of HIVST-online made by a peer HIVST-online user. Another video demonstrating the use of HIVST (two minutes) will be sent to prospective participants; such a video is available from the ongoing project. Knowing that HIVST is easy to use would increase perceived confidence and hence self-efficacy (a Health Belief Model construct) in taking up HIVST-online.