function openWindow(url, window_name)
{
    var _WindowName = "_blank";
    if (window_name) {
        _WindowName = "window_name";
    }
    
    var _Top = 80;
    var _Left = 80;
    
    var _MaxWidth = 580;    
    var _Width = _MaxWidth; 
    var _Height = 550;
    if (window.screen) {
        _Height = (window.screen.availHeight - _Top)*0.8;
        _Width = (window.screen.availWidth - _Left)*0.8;
    
    }
    if (_Width > _MaxWidth) { _Width = _MaxWidth; }
    
    var _Toolbars = 0;
    var _Location = 0;  //navbars
    var _Directories = 0;
    var _Statusbar = 0;
    var _Menubar = 1;
    var _Scrollbars = 1;
    var _Resizable = 1;
    
    var _WindowControls = "toolbar=" + _Toolbars + ",location=" + _Location;
    _WindowControls = _WindowControls + ",directories=" + _Directories + ",status=" + _Statusbar;
    _WindowControls = _WindowControls + ",menubar=" + _Menubar + ",scrollbars=" + _Scrollbars;
    _WindowControls = _WindowControls + ",resizable=" + _Resizable;
   
    window.open(url, _WindowName, "" + _WindowControls + ",width="+_Width+",height="+_Height+",left="+_Left+",top="+_Top);

}