Passing parameters from one OAF page to another OAF PAge

// processFormRequest()
HashMap hm = new HashMap(1);
hm.put("myParam", "myParamVal");
oapagecontext.setForwardURL("MY_FUNCTION", (byte)0, null, hm, true, "N", (byte)0);

You can then retrieve this parameter in processRequest() via:
oapagecontext.getParameter("myParam")