var propup = function(o) {

    o.url = (typeof o.url == 'undefined') ? 'http://www.emanueleferonato.com/2007/09/21/complete-javascript-popup-opener/' : o.url;

    o.width = (typeof o.width == 'undefined') ? screen.width/2 : o.width;

    o.height = (typeof o.height == 'undefined') ? screen.height/2 : o.height;

    if((o.width<=1)&&(o.width>0)){o.width*=screen.width}

    if((o.height<=1)&&(o.height>0)){o.height*=screen.height}

    o.xpos = (typeof o.xpos == 'undefined') ? (screen.width/2)-(o.width/2) : o.xpos;

    o.ypos = (typeof o.ypos == 'undefined') ? (screen.height/2)-(o.height/2) : o.ypos;

    o.xoffset = (typeof o.xoffset == 'undefined') ? 0 : o.xoffset;

    o.yoffset = (typeof o.yoffset == 'undefined') ? 0 : o.yoffset;

    o.name = (typeof o.name == 'undefined') ? 'propup' : o.name;

    o.scrollbars = (typeof o.scrollbars == 'undefined') ? 'no' : o.scrollbars;

    o.resizable = (typeof o.resizable == 'undefined') ? 'no' : o.resizable;

    o.status = (typeof o.status == 'undefined') ? 'no' : o.status;

    o.locat = (typeof o.locat == 'undefined') ? 'no' : o.locat;

    o.toolbar = (typeof o.toolbar == 'undefined') ? 'no' : o.toolbar;

 

    if(o.xpos == "left"){o.xpos=0;}

    if(o.xpos == "right"){o.xpos = screen.width-o.width;}

   

    if(o.ypos == "top"){o.ypos=0;}

    if(o.ypos == "bottom"){o.ypos = screen.height-o.height;}

   

    o.xpos += o.xoffset

    o.ypos += o.yoffset

 

    var scrollbarstext = 'scrollbars = '+o.scrollbars+",";

    var resizabletext = 'resizable = '+o.resizable+",";

    var statustext = 'status = '+o.status+",";

    var locationtext = 'location = '+o.locat+",";

    var toolbartext = 'toolbar = '+o.toolbar+",";

 

    features = scrollbarstext+resizabletext+statustext;

    features = features + locationtext+toolbartext;

    features = features + 'width = '+o.width+',height = '+o.height;

    features = features + ',top = ' + o.ypos;

    features = features + ',left = ' + o.xpos;

       

    var win = null;

    win = window.open(o.url, o.name, features);

}