can't access 2724 in managed mode

Hi

i have a Dell Powerconnect 2724 switch that i can't access

i have set my laptop to 192.168.2.2, subnet to 255.255.255.0 i set the switch to managed mode by pressing the managed button with a paperclip and wait for the managed mode light to go steady and when i open a browser and type in 192.168.2.1 the browser says, "the address is not valid.

is there a way to reset the switch to the default factory values?

thanks

Jody