There is javascrit functio is calling on button click and this form get created by Iframe i just want to set link to be open in new tab or window

 top.location.href=queryString;
            return false;

            this is redirection link but opening is same page I want this to be open in new window or tab 

            remeber this line is inside iframe block 

you are looking for the javascript function window.open (or, in your case, top.window.open("https://www.yahoo.com") or whatever....)