def ZeroIndex(runs,dia,runindex):
    """
   #accumulate indexes  
    Args:
      dia:diagonal indexes returned from function DiagonalZero
      runs:start and stop indexes
   Results:
     indexlst: list of indexes
    """
    i=runs[0]
    j=runs[1]
    indexlst=[]
    for i in range(i,j):
       indexlst+=[dia[i]]

    return indexlst