Open CRM Lookup window in a custom page

function OpenLookup() {

    var serverURL = "http://Server:5555/OrganizationName/_controls/lookup/lookupinfo.aspx?AllowFilterOff=1&DefaultType=2&DefaultViewId=%7b00000000-0000-0000-00AA-000010001004%7d&DisableQuickFind=0&DisableViewPicker=0&LookupStyle=single&ShowNewButton=1&ShowPropButton=1&browse=0&objecttypes=123";

    var lookUp = window.showModalDialog(serverURL, 'entity', "dialogwidth: 750px; dialogheight: 600px; resizable: yes");

    ///For get return values

    //var name = lookUp.items[0].name; var id = lookUp.items[0].id;

    if (lookUp != null) {

        var data = eval('(' + lookUp + ')');

        alert(data.items[0].name + ":" + data.items[0].id);

    }

}