Disable Event Receivers During an Item Update/ Stop recursive call of event handler during item update

It's very simple. 

Write the below code at the start of your function(in event receiver function)

public override void ItemUpdating(SPItemEventProperties properties)
{

            this.EventFiringEnabled =false;

          

                //your code here........................

           this.EventFiringEnabled =true;

}

Don't forget to enable it again at the end of you function.