code: public String getScreenURL()
      {
          String strURL = super.getScreenURL();
          ReferenceField fldContactType = (ReferenceField)this.getScreenRecord().getField(MessageLogScreenRecord.CONTACT_TYPE_ID);
          String strContactTypeParam = fldContactType.getFieldName();
          if (!fldContactType.isNull())
          {
              String strContactType = fldContactType.getReference().getField(ContactType.CODE).toString();
              strURL = this.addURLParam(strURL, strContactTypeParam, strContactType);
          }
          return strURL;
      }
docs: Get the command string to restore screen.