`if(trigger.isUpdate)
    {	integer  i=0;
	list<AccountOne__c> a2 = new list<AccountOne__c>([Select Id from AccountOne__c where Name =: trigger.old[i].Name ]); 
	for(AccountOne__c c1 : a2)
	{	
	
		
		c1.Name=trigger.new[i].name;
		c1.Fax__C =trigger.new[i].Fax;
		c1.Phone__C=trigger.new[i].Phone;
		i++;
		}
		update a2;
        }`
i tried bulk trigger for the update operation ,but its not working can anyone help me