Hello i want to create contact and opportunity from Accounts detail page by using button.

i created controller extention but it created contact and opportunities they are not related to that particular account.

 here is my code :
public class OppClass3
    {
      Public Account Account;
      public Opportunity opportunity;
      public contact contact;
      public string ConName {get;set;}
      public String fstName {get;set;}
      public string Email{get;set;}
      public string conacc{get;set;}
      public string oppacc{get;set;}
      public string Phone {get;set;}
      public String OppName{get;set;}
      public Date d {get;set;}
     
    private final Account acc;
     public String OpportunityName {get;set;}
public String OpportunityStage {get;set;}
public Date ClosedDate {get;set;}
                
     public OppClass3(ApexPages.StandardController stdController) {
        this.acc= (Account)stdController.getRecord();
     }
 
      public account getAccount()
      {
      if(account == null)
      {
      Account = new Account();
      system.debug('Account------>'+account);
      
      }
      return Account;
      }
          
          public contact getcontact()
          {
          
          if(contact==null)
          contact = new contact();
          System.debug('contact--->'+contact);
          return contact;
          
          
          }
          
          public Opportunity getOpportunity()
          {
          if(opportunity == null)
          opportunity = new opportunity();
          
          System.debug('opportunity--->'+opportunity);
          return opportunity;
          
          }
 
    public PageReference NewOpp(){
         opportunity = new opportunity();
         contact = new contact();
        
               return new PageReference('https://sreeee.ap1.visual.force.com/apex/page14');
 
        }
        
        public PageReference mySave()
        {
        
        
        contact = new contact(lastname = conname,firstname = fstName,Email = email,phone = phone,accountid=acc.id );
        //contact.accountid = account.id;
        insert contact;
        
        
        
        opportunity = new opportunity(name = OppName,StageName='New Opportunity',CloseDate=d,accountid=acc.id);
       // opportunity.accountid = account.id;
        insert opportunity;
        
        PageReference pr = new Apexpages.StandardController(contact).view();
        
        
        pr.setRedirect(true);
         PageReference pr1 = new Apexpages.StandardController(opportunity).view();
        
        
        pr1.setRedirect(true);
        
      return new PageReference('https://sreeee.ap1.visual.force.com/apex/page14');
      // return null;
        
        }
 
}
<apex:page standardcontroller="Account" extensions="OppClass3">
    <apex:form >
 <apex:pageBlock >
 <apex:pageBlockButtons >
  <apex:commandButton value="Save" action="{!mysave}"/>
 <apex:commandButton value="Cancel" action="{!cancel}"/>
 <apex:commandButton value="New opp" action="{!NewOpp}"/>
</apex:pageBlockButtons>

<apex:pageBlockSection title="Contact Information">
<apex:pageBlockTable value="{!contact}" var="o">
<apex:column headerValue="LastName"><apex:inputText value="{!ConName}"/></apex:column>

<apex:column headerValue="FirstName"><apex:inputText value="{!fstName}"/></apex:column>
<apex:column headerValue="phone"><apex:inputText value="{!phone}"/></apex:column>
<apex:column headerValue="Email"><apex:inputText value="{!Email}"/></apex:column>
<apex:column headerValue="AccountName"><apex:inputField value="{!o.accountid}"/></apex:column>
</apex:pageBlockTable>
</apex:pageBlockSection>


   <apex:pageBlockSection title="Opportunity Information">
   <apex:pageBlockTable value="{!Opportunity}" var="o">
   
   <apex:column headerValue="OpportunityName">
   <apex:inputText value="{!OppName}"/> </apex:column>
   <apex:column headerValue="AccountName"><apex:inputField value="{!o.accountid}"/></apex:column>
   <apex:column headerValue="Stage" >
   <apex:inputField value="{!o.stagename}"/> </apex:column>
    <apex:column headerValue="CloseDate" ><apex:inputText value="{!d}"/> </apex:column>
   
  </apex:pageBlockTable>
   
          <!-- <apex:pageBlockSectionItem >
                   <apex:outputLabel value="Opportunity Name"/>
                   <apex:inputText value="{!opportunityName}" />
           </apex:pageBlockSectionItem>
             
           <apex:pageBlockSectionItem >
                   <apex:outputLabel value="Opportunity Amount"/>
                  <apex:inputText value="{!opportunitystage}" />
           </apex:pageBlockSectionItem>
            <apex:pageBlockSectionItem >
                   <apex:outputLabel value="ClosedDate"/>
                  <apex:inputText value="{!ClosedDate}" />
           </apex:pageBlockSectionItem>
            
            <apex:pageBlockSectionItem >
                    <apex:outputLabel value="AccountName"/>
                    <apex:outputField Value="{!Account.name}"/>
            </apex:pageBlockSectionItem>-->
    </apex:pageBlockSection>
</apex:pageBlock>
</apex:form>
</apex:page>

Thanks in advance !!!!