input: Write a function to generate a list of random numbers within a specified range and length. If the length is zero or negative, return an empty list.
  assert generate_random_numbers(5, 1, 10)==[<float_numbers>]
  assert generate_random_numbers(3, -5, 5)==[<float_numbers>]
  assert generate_random_numbers(0, 1, 10)==[]
  assert generate_random_numbers(-3, 1, 10)==[]
  assert generate_random_numbers(10, -10, 10)==[<float_numbers>]
output: import random
  
  def generate_random_numbers(length, start, end):
      if length <= 0:
          return []
      return [random.uniform(start, end) for _ in range(length)]