Trigger in salesforce

Hi,

Try this -

Class code 
public class checkRecursive {
     public static Set<Id> SetOfIDs = new Set<Id>();
}

In order to avoid the situation of recursive call, make sure your trigger is getting executed only one time. To do so, you can create a class with a Static Set

Check if the record exists in the set, if so do not execute the trigger, else execute the trigger.

NOTE: Before deploying into production, we recommend testing in sandbox.

This is a sample code written for Account object Class code
public class checkRecursive {
public static Set<Id> SetOfIDs = new Set<Id>();
}
Trigger code 
trigger TestTrigger on Account (before insert) {
    if (Trigger.isAfter && Trigger.isInsert) {
        List<Account> accList = new List<Account>();
      for (Account test: Trigger.new) {
          If(!checkRecursive.SetOfIDs.contains(test.Id)){
              test.Name = 'helloworld'; 
              accList.add(test);
            checkRecursive.SetOfIDs.add(test.Id);
          }
      }
      insert  accList;
    }
}

Hope this helps.