My SDL needs sound alert... Help!

[rsbgm]

Dear Anyone,

I have attached a custom indicator for a Slope Direction Line that changes color as it changes direction... blue for uptrend and red for downtrend. I also need it to have an option to alert me whenever the trend changes. I can't figure out from the iteration what variable to use for conditions, and, i'm not sure which line do I put the code. But I suppose the command alert is very easy to encode. Please help to finalize the coding.

Attached is the indicator. I just had the alert line in comments at the moment. Please review and HELP!