Ori, I finally found the PageContext.Guid property by inheriting my page from Gizmox.WebGUI.Forms.Hosts.AspPageBase (not from Gizmox.WebGUI.Forms.Hosts.AspPipeLinePage). Now then problem is than my script fails when trying to create the event here:
var objEvent = Events_CreateEvent(mintGuid, "VwgReadHtmlInput", null, true);
It seems the the Events_CreateEvent function cannot be found.
What am I doing wrong? Thank you very much.