Dear all, I`m new to apex and I need help with issue below. I have a "New Case" custom button on Opportunity record which allows me to create Case. When clicked on "New Case" button, I can select record type and page gets redirected to standard page or visualforce page using redirect class below. Code works fine but I`m unable to auto-populate fields when record type with standard page is selected. Fields are not getting auto populated the way it happens with standard functionality. For example, I`m not able to auto-populate Opportunity Name, Stage or Close Date while creating new case record. Can someone please help? Any help is much appreciated. Thank you!

Redirect VF page

<apex:page standardController="Case" extensions="Redirect" action="{!Redirect}">

</apex:page>

Redirect class
 

public with sharing class Redirect{

    private Id id;


 private ApexPages.StandardController controller;
 public String retURL {get; set;}
 public String saveNewURL {get; set;}
 public String rType {get; set;}
 public String cancelURL {get; set;}
 public String ent {get; set;}
 public String confirmationToken {get; set;}


 public Redirect(ApexPages.StandardController controller) {

  this.controller = controller;
  retURL = ApexPages.currentPage().getParameters().get('retURL');
  rType = ApexPages.currentPage().getParameters().get('RecordType');
  cancelURL = ApexPages.currentPage().getParameters().get('cancelURL');
  ent = ApexPages.currentPage().getParameters().get('ent');
  confirmationToken = ApexPages.currentPage().getParameters().get('_CONFIRMATIONTOKEN');
  saveNewURL = ApexPages.currentPage().getParameters().get('save_new_url');
 }

 
 public PageReference redirect(){
  
  PageReference returnURL;
  // Redirect if Record Type corresponds to custom VisualForce page
  if(rType == '0121b0000009t60') {
   returnURL = new PageReference('/apex/vfcasepage');
  }
  else {
   returnURL = new PageReference('/500/e?nooverride=1');
  }

  returnURL.getParameters().put('retURL', retURL);
  returnURL.getParameters().put('RecordType', rType);
  returnURL.getParameters().put('cancelURL', cancelURL);
  returnURL.getParameters().put('ent', ent);
  returnURL.getParameters().put('_CONFIRMATIONTOKEN', confirmationToken);
  returnURL.getParameters().put('save_new_url', saveNewURL);
    returnURL.getParameters().put('nooverride', '1');
  returnURL.setRedirect(true);
  return returnURL;

 }

 public PageReference cancel() {
          PageReference pr = new PageReference('/500/o');
          pr.setRedirect(true);
          return pr;
     }


}