st: how to cancel the seed set previously?

[gjhxmu@sina.com]

I set seed # before the runiform() function.
For instance,
I typed,
set seed 100
g x=runinform()

my confusions are,
1.how to set the seed number propriately? I saw everyone set it large.Any difference?
2. how to cancel the seed set previously? Maybe next time I again want to produce uniformly distributed random variates, and set seed 100 by accident , which may lead to the variates produced is not random.

Thank you for any replies!

Sincerely,
from Rose.

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