Today, I tried to control a html link with a tag and a function (in c#) like the following, <a href="<%#GetTopLink(Eval... protected string GetTopLink(string vUrl) { if (<true>) return vUrl; else return "javascript: window.open('" + vUrl + "','new'); void(0);"; } It doesn't seems it's a very smart way. A reminding to myself, <a href="http://www.microsoft.... target="_blank">go</a... <a href="http://www.microsoft....