---------Apex controller-------------------

public class sale
{
    public string reas{get; set;}
    public String Index{get; set; }
    public String s{get; set; }
    public List<wclass> sal1{get; set;}
    public List<Selectoption> options;
    public Decimal tval1{get; set;}
    public sale() 
    {
        sal1=new list<wclass>();
        sal1.add(new wclass(new Sales__c(),new list<selectoption>(),0 ));        
    }
    public void c1show()
    {
        options = new List<SelectOption>();
         s=System.currentPageReference().getParameters().get('sss');
        List<Contact> c=new List<Contact>();
        c=[select id,name from contact where Account.Id=:s];
        for(contact c1:c)
        {
            options.add(new SelectOption(c1.id,c1.name));
        }
        Account a=[select AnnualRevenue from account where id=:s];
        tval1=a.AnnualRevenue;
        String q=String.valueOf(tval1);
        System.debug(q);
        for(Integer i=0;i<sal1.size();i++)
        {
            if(s==sal1.get(i).l1.Aname__c)
            {
                sal1.set(i,new wclass(new Sales__c(),options,tval1));
            }
        }
    }
    public void ar()
    {
        wclass s1 =new wclass(new Sales__c(),new list<selectoption>(),0.0);
        sal1.add(s1);
    }
    public void rmv()
    {
        Integer rm=Integer.valueOf(ApexPages.currentPage().getParameters().get('Index'));
        System.debug(rm);
        sal1.remove(rm-1); 
    }
    public void gpdf()
    {
        reas='pdf';
    }
    public class wclass
    {
        public Sales__c l1{get;set;}
        public list<selectoption> ls{get;set;}
        public Decimal tval {get; set;}
        public wclass(Sales__c s1, list<selectoption> s2,Decimal s3)
        {
            l1=s1;
            ls=s2;
            tval=s3;
        }
    }
}

--------------test class---------------------


@isTest (SeeAllData = true)
private class salestest{
    public static testMethod void testMyController() {
         PageReference pageRef = Page.sales; 
         sale saletest =new sale();
        Test.startTest();
        saletest.reas='pdf';
         saletest.tval1=35000000;
        saletest.s='0012800000Mw6WV';
        saletest.Index='2';
        Account a=[select AnnualRevenue from account where id=:saletest.s];
        contact c1= new contact();
       // c1.name='akshit';
         saletest.c1show();
         saletest.ar();
         saletest.rmv();
        saletest.gpdf();
        Test.stopTest();
    }
 }