Blogroll question

When someone clicks a link on my blogroll, the link opens in the same window. I’d like to figure a way to have that link open in a new window, the firefox or ie, allow a link to open in a new window? But no code I add to the url line makes that happen, in fact most of them render the link unusable. Is there a way to direct the link to open in a new window or tab? Thanks! :^) gene