QUOTE:
its naturally working fine on strategy window
It's certainly not going to generate Alerts in the S. Window either though.
It's because signals will not generate an Alert unless you execute them on the next bar, i.e.,
bar + 1. When you program signals for "AtClose" it generally means you want to sell it at the close of the current bar even though you cannot really do this in real trading. In other words, since the close has already occurred, you cannot execute a signal at the close.
For more discussion and solutions, see the WealthScript Programming Guide (Help menu) > Programming Trading Strategies > Alerts > How to: Alert for AtClose Signals
(And of course, if this is an intraday Strategy, then the solution is to simply change your signals to AtMarket. For intraday intervals, the difference between the Close of one bar and the Open of the next is only 1 trade and it would be silly to think you can capture the Closing price on an intraday basis.)