// POPUP

function isUndefined(a) { return typeof a == 'undefined' }

function raw_popup(url, target, features) {
    // pops up a window containing url optionally named target, optionally having features
    if (isUndefined(features)) features = _POPUP_FEATURES;
    if (isUndefined(target  )) target   = '_blank';
    var theWindow = window.open(url, target, features);
    theWindow.focus();
    return theWindow;
}

function link_popup(src, features) {
    // to be used in an html event handler as in: <a href="..." onclick="link_popup(this,...)" ...
    // pops up a window grabbing the url from the event source's href
    return raw_popup(src.getAttribute('href'), src.getAttribute('rel') || '_blank', features);
}

function event_popup(e) {
    // to be passed as an event listener
    // pops up a window grabbing the url from the event source's href
    link_popup(e.currentTarget);
    e.preventDefault();
}

function event_popup_features(features) {
    // generates an event listener similar to event_popup, but allowing window features
    return function(e) { link_popup(e.currentTarget, features); e.preventDefault() }
}

function OpenImage(src, width, height) { 
	return raw_popup(src.getAttribute('href'), '_blank', 'width=' + (width + 20) + ',height=' + (height + 20) + ',top=' + ((screen.width - width + 20) / 2) + ',left=' + ((screen.height - height + 20) / 2) + ',scrollbars=0,location=0,statusbar=0,menubar=0') 
}


// redefining default features
var _POPUP_FEATURES = ''