As we know, we cannot open a URL link by using ironpython button, so the button I developed only creates a link in a textarea control
dynamic.As[HtmlTextArea]().HtmlContent = "<a href=\"" + varurl + "\">Link" + "</a>"
At the textarea, I added a JavaScript just like below to listen to the URL in the textarea
window.open(document.links[0].href,'_blank');
But the JavaScript asl brings an issue, each time the user switches to this tab, the script will be also triggered to open a new page to the URL, is that possible to set the script to only run once? Just after the ironpython button clicked.