Source code for an ARIMA model

Hi,
I am looking at implementing a ARIMA model. I do have some background
in satistics and math long time ago, but have lost touch with much of
it lately. The data I am dealing with is the number of rows loaded to
a table once every month. I would like to predict the number of
rows to be processed for an upcoming month, and if the actual rows
processed falls below a confidence level of 95% I need to be notified.
Is there a source code out there written in any language which would
take a set of descrete values, and create a ARIMA model. I need the
source code so that i can implement that in my environment. Any
pointers ?
Thanks.
Jay

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