?new window with java

I’m opening .jpg pictures in a new window and I modify the window with
javascript for exemple:

                                         getURL("javascript:n_name = window.open('photo1.jpg','new_name1','scrollbars=no,resizable=yes,toolbar=no,width=680,height=447');void(0);");
}

its working but I get a few pixels wide white borderline on the left side and on the top. Does anybody know why?