function GetCenteredLeft(Width) {
        return (screen.width - Width) / 2;
    }

    function GetCenteredTop(Height) {
        return (screen.height - Height) / 2;
    }

    function OpenWindow(URL, Name, Width, Height) {
        // Ανοίγει ένα κεντραρισμένο στην οθόνη παράθυρο 
        var l = GetCenteredLeft(Width);
        var t = GetCenteredTop(Height) - 50;

        var win = window.open(URL, Name, "resizable=yes,toolbar=no,scrollbars=yes,left=" + l + ",top=" + t + ",width=" + Width + ",height=" + Height + ",directories=no,status=yes,menubar=no,dependent=yes");
        win.focus();
    }

    function OpenDialog(URL, Name, Width, Height) {
        var ret;
        if (document.all) {
            root = 'http://www.nessi-europe.net/';
            ret = window.showModalDialog(root + "Admin/Forms/OpenDialog.aspx?URL='" + URL + "'", Name, "center:yes;resizable:yes;help:no;dialogWidth:" + Width + "px;dialogHeight:" + Height + "px;status=yes;scroll:no");
        }
        else
            ret = window.showModalDialog(URL, Name, "center:yes;resizable:yes;help:no;dialogWidth:" + Width + "px;dialogHeight:" + Height + "px;status=yes;scroll:yes");
            
		    if (Name == "PagesTreeView") {
		        window.location = window.location.href;
		        window.location.search = "page=" + ret;
		        window.parent.window.location = window.parent.window.location.href;
		        window.parent.window.location.search = "page=" + ret;
		    }
		    else {            
                window.location = window.location.href;
            }
            
        return ret;
    }

    function OpenZoomedDialog(URL, Name) {
        return OpenDialog(URL, Name, screen.width - 20, screen.height - 20);
    }

    function OpenDialogNoFrame(URL, Name, Width, Height) {
        window.open(URL, Name, 'width=' + Width + ',height=' + Height + ',resizable=yes,location=yes,toolbar=yes');
    }
    
    //UPDATE SORT ORDER ASYNCH
    function UpdateSortOrder(PagePortletID, SortOrderTextBox)
    {        
        var text = document.getElementById(SortOrderTextBox).value;        
        if (text != null && text != "")
        {
            //alert(PagePortletID + "," + text)       
            $.ajax({ type: "POST",
              data: "{'PagePortletID':'" + PagePortletID + "','SortOrder':'" + text + "'}",
                  url: "WebServices/wsUpdateSortOrder.asmx/wsUpdateSortOrderByPagePortletID",
                  contentType: "application/json; charset=utf-8",
                  dataType: "json", success: OnSuccessSorting, error: OnErrorSorting
              });
        }
    }
    
    function OnSuccessSorting(data, status) {
         alert('Η θέση ενημερώθηκε με επιτυχία.');
     }
     
     function OnErrorSorting(data, status) {
         alert('ΣΦΑΛΜΑ στην ενημέρωση της θέσης.');
     }  
    //UPDATE SORT ORDER ASYNCH END