now i am getting err like this Compile Error: Method does not exist or incorrect signature am getting this line err  getList2Details() ....

public string Level;           
public String getLevel() 
{
return Level;
}
public void setLevel(String Level) 
{ 
this.Level= Level; 
}
/*cuslevel start  */

    public class Level1sClass 
    {
        public String accURL;
        public string acid1{ get; set; }
        public Level1s__c lev1{ get; set; }
        public Level1s__c lev1Tree{ get; set; }
       // public Level1__c lev1AccTree{ get; set; }
        public Level1__c lev1IDTree{ get; set; }
        public List<Level2sClass> lev2 {get; set;}
        public List<Level2sClass> lev2Tree {get; set;}
        public integer chkcountL1 {get; set;} 
        public Boolean selected {get; set;}
        public Level1sClass(Level1s__c gp)
        {
            accURL= ApexPages.currentPage().getParameters().get('id');
            lev1 = gp;
            lev1Tree = gp;
            acid1 = accURL;
        /*    List<Level1__c> treelst1 = [Select Level1__c,Name,CusLevel1Name__c, AccountName__c, Account__c ,cLevel1__c from Level1__c where Account__c=:accURL];
            for(Level1__c le1: treelst1)
            {
             lev1IDTree =  le1;
             
            } */
           
            lev2 = getList2Details(gp); 
          //  lev2Tree = getTreeLevel2list(gp);
           
            if(accURL!= '' && accURL!= null)
            {
                  chkcountL1 = gp.Level1s__r.size();
                    if(chkcountL1  > 0 )
                        {
                            selected = true;
                           
                        }
                        else
                        {
                            selected = false;
                              
                        }
                      
             }  
 
        }
     }       
    public class Level2sClass
    {
        public String accURL;
        public level2s__c lev2 {get; set;}
        public level2s__c lev2Tree {get; set;}
        public Level2__c lev2IDTree{ get; set; }
        public List<Level3sClass> lev3 {get; set;}
        public List<Level3sClass> lev3Tree {get; set;}
        public Boolean selected {get; set;}
        public integer chkcountL2 {get; set;} 
        public Level2sClass(Level2s__c l2)
        {
           accURL= ApexPages.currentPage().getParameters().get('id');
           lev2 = l2;
           lev2Tree = l2;
         /*  List<Level2__c> treelst2 = [Select Level2__c,Name,CusLevel2Name__c, AccountName__c, Account__c ,cLevel2__c from Level2__c where Account__c=:accURL];
            for(Level2__c le1: treelst2)
            {
             lev2IDTree =  le1;
             
            } */
           lev3 = getList3Details(l2);
          // lev3Tree = getTreeLevel3list(l2);
          
           chkcountL2  = l2.Level2s__r.size();
            if(chkcountL2  > 0 )
            {
                selected = true;
               
            }
            else
            {
                selected = false;
                  
            }           
        }
    } 
 /* $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ Save $$$$$$$$$$$$$$$$$$$$$$$$$$$$$ */


public PageReference Save()
{
   List<level1s__c> selectLevel1 = new List<level1s__c>();
     
       
    //this.stdController.save();
    

    /////////// LEVEL1 ///////////////////
    List<level1s__c> selectedLevel1 = new List<level1s__c>(); 
    
    for(Level1sClass cCon: getList1Details() )
    {
         system.debug('cCon'+cCon.selected);
        if(cCon.selected == true)
        {
            system.debug('firstCCCCCCCCCC:'+cCon.lev1);
            selectedLevel1.add(cCon.lev1);
        }
    }           
     
    Level1__c[] levl1= [Select Id from Level1__c where Account__c=: ApexPages.currentPage().getParameters().get('id')]; 
    delete levl1; 
    if(selectedLevel1 != null)
    {     
        for(level1s__c con : selectedLevel1)
        {
            system.debug('CCCCCCCCCC:'+con+'\n');
            string acctid =ApexPages.currentPage().getParameters().get('id');
            List<Level1__c> lvl1obj= new  Level1__c[0];
            lvl1obj.add(new Level1__c(Name='Level1',Account__c=acctid,cLevel1__c=con.id));
            insert lvl1obj;
    
        }
    }    
    //////////// LEVEL2 ////////////////////
    List<level2s__c> selectedLevel2 = new List<level2s__c>(); 
    
 
    for(Level2sClass cCon:getList2Details())
    {
    
         system.debug('cCon'+cCon.selected);
        if(cCon.selected == true)
        {
            system.debug('firstCCCCCCCCCC:'+cCon.lev2);
            selectedLevel2.add(cCon.lev2);
        }
    }           
     
    Level2__c[] levl2= [Select Id from Level2__c where Account__c=: ApexPages.currentPage().getParameters().get('id')]; 
    delete levl2; 
    if(selectedLevel2 != null)
    {     
        for(level2s__c con : selectedLevel2)
        {
            system.debug('CCCCCCCCCC:'+con+'\n');
            string acctid =ApexPages.currentPage().getParameters().get('id');
            List<Level2__c> lvl2obj= new  Level2__c[0];
            lvl2obj.add(new Level2__c(Name='Level2',Account__c=acctid,cLevel2__c=con.id));
            insert lvl2obj;
           
         }
    }
  
    return null;
    
}