//Returns a time stamp with year, month, day, hour and four random characters

public String timeStamp(){

 //start string with year
  String stamp = ""+year();

 //add month with two characters
  if(month()<10)stamp += "0"+month();  
  else stamp+= month();

 //add day with two characters
  if(day()<10)stamp += "0"+day();  
  else stamp+= day();

 //add hour with two characters
  if(hour()<10)stamp += "0"+hour();  
  else stamp+= hour();

 //add minute with two characters
  if(minute()<10)stamp += "0"+minute();  
  else stamp+= minute();

 //add second with two characters
  if(second()<10)stamp += "0"+second();  
  else stamp+= second();

 //add slash and four letters
  stamp+= "-"+char(int(random(97,122)));
  stamp+= char(int(random(97,122)));
  stamp+= char(int(random(97,122)));
  stamp+= char(int(random(97,122)));

  return stamp;
}