Timing

The Timing of a limit order is chosen on a pull-down menu:

Day Only	If the order is not filled by the end of the day, it is canceled. Fill or Kill. If the order is not filled immediately and in its entirety, it is canceled.
Good Until Canceled	The order is kept in the system for 30 days or until it is executed. If the order has not been executed in 30 days you will receive a message requesting you to leave or cancel the order. (See Do Not Reduce below.)
Immediate or Cancel	If the order is not executed immediately, it is canceled. If part of the order is executed immediately, the remainder of the order is canceled.

Other Options

Any or all of three order options may be chosen.

All or None	The order must be executed in its entirety or not at all. Can be used with Day Only or Good Until Canceled.
Do Not Reduce	This option causes the ex-dividend dates of the stocks that comprise an order to have no effect on an orders limit price. If the box is not checked (default), then on an ex-dividend date the stocks per-share limit price is reduced or the debit/credit limit for the order is changed to reflect the ex-dividend amount. Example. Stock XYZ goes ex-dividend in the amount of $0.10 on day T. All per-share limit prices for XYZ are reduced by 0.10 as of the beginning of the trading day on day T, unless the Do Not Reduce option is selected. Also, all debit/credit limits are raised(lowered) by $0.10 times the number of shares of XYZ being sold(bought).
Minimum Sell Side Shares	A trade may not take place unless at least the indicated number of sell-side shares (and the prorata portion of buy-side shares) is executed in one trade. After the minimum number of shares has been traded, the rest of the order has no minimum.