// These defaults should be changed the way it best fits your site
var _POPUP_FEATURES = 'width=820,height=820,location=no,menubar=no,status=no,scrollbars=yes';
//width=800,height=800,

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('target') || '_blank', features);
	}

function isUndefined(v)
	{
    var undef;
    return v===undef;
	}