Warning Alerts Depending On Time Remaining To Finish Task

[peter renton]

Hi
I have attched a workbook,

When the time required for is entered in column J column k counts down the time left to complet the job, the cell goes red with one
hour to go.

is it possible to do the following:-

When the half hour left is reached a warning alert message box and or audio alert is shown, but if the completed box is selected in column P the alerts are disabled and the time frozen in K ???

Regards


Peter