Creating View Object and MessageChoiceBean Programatically

Controller Code

public void processRequest(OAPageContext pageContext, OAWebBean webBean)
{
super.processRequest(pageContext, webBean);
String sMode = "test";
OAApplicationModule am = pageContext.getApplicationModule(webBean);
OAViewObject oaviewobject = (OAViewObject)am.findViewObject("xxScoResourceVO1");
if(oaviewobject == null)
{
oaviewobject = (OAViewObject)am.createViewObject("xxScoResourceVO1","xx.oracle.apps.pa.poplist.server.xxScoResourceVO");
}
      
oaviewobject.setWhereClause("DESCRIPTION IS NULL OR DESCRIPTION = '" + sMode + "'"); //Setting where clause Dynamically of Poplist VO

oaviewobject.executeQuery();
OAMessageChoiceBean oamessagechoicebean = (OAMessageChoiceBean)createWebBean(pageContext, "MESSAGE_POPLIST");
oamessagechoicebean.setPrompt("Back");
oamessagechoicebean.setListViewObject(pageContext, oaviewobject);
oamessagechoicebean.setListDisplayAttribute("Meaning");
oamessagechoicebean.setListValueAttribute("LookupCode");
  
oamessagechoicebean.setName("xxAddAsgmtApplyAction");
oamessagechoicebean.setAllowBlankValue(false);
oamessagechoicebean.setDefaultValue("RETURN_BACK"); //Setting Default Value
webBean.addIndexedChild(oamessagechoicebean);
}

How to capture its Value

String PoplistValue = oapagecontext.getParameter("xxAddAsgmtApplyAction");