Edimax Technology 3G-6210n manual Delete a time. If the QoS table is empty, this button, Clicked

Here are descriptions of every setting:

Enable QoS (1):	Check this box to enable QoS function, unselect this
	box if you don’t want to enforce QoS bandwidth
	limitations.
Total Download	You can set the limit of total download
Bandwidth (2):	bandwidth in kbits. To disable download bandwidth
	limitation, input ‘0’ here.
Total Upload	You can set the limit of total upload
Bandwidth (3):	bandwidth in kbits. To disable upload bandwidth
	limitation, input ‘0’ here.
Current QoS	All existing QoS rules will be displayed here.
Table (4):
Add (5):	Click ‘add’ button to add a new QoS rule, see
	section 3-1-2 ‘Add a new QoS rule’ below.
Edit (6):	If you want to modify the content of a specific rule,
	please check the ‘select’ box of the rule you want to
	edit, then click ‘Edit’ button. Only one rule should
	be selected a time! If you didn’t select a rule before
	clicking ‘Edit’ button, you’ll be prompted to add a
	new rule.
Delete	You can delete selected rules by clicking this
Selected (7):	button. You can select one or more rules to delete by
	check the ‘select’ the box of the rule(s) you want to
	delete a time. If the QoS table is empty, this button
	will be grayed out and can not be clicked.
Delete All (8):	By clicking this button, you can delete all rules
	currently in the QoS table. If the QoS table is empty,
	this button will be grayed out and can not be
	clicked.

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