Seems that (try at jsfiddle)
window.open(\'http://www.google.com/\', window_name, \'width=400,height=320\');
completely stops opening new w
Your fiddle does not contain the code that you posted. This one just works fine: http://jsfiddle.net/HLbLu/
Note that for some reason calling window.open(...) is not the same as calling open(...).
window.open(...)
open(...)