The opportunity Stage name is modified as closed own then set close date as today and customer as a new customer using trigger(Before Update)

When a new record is created in account object before a new record is inserted into account, delete all the contact records with this account name

Hi,

trigger contactrecords on Account (before insert)
 {

    List<String> myname=new List<String>();
    for(Account a:trigger.new)
    {
    myname.add(a.name);
    }
    List<contact> mycontact=[select id,name from contact where name in:myname];
    delete mycontact;
}

Please help me.