Silly question on subnetting

in CCNA & CCENT
I tried to assign the follow IP address to VLAN1 in Packet Tracer and this is what I get.
Switch0(config-if)#ip address 192.168.1.0 255.255.255.0
Bad mask /24 for address 192.168.1.0
Can someone plz explain..
Switch0(config-if)#ip address 192.168.1.0 255.255.255.0
Bad mask /24 for address 192.168.1.0
Can someone plz explain..
Comments
network- 192.168.1.0
first host - 192.168.1.1
last host - 192.168.1.254
broadcast - 192.168.1.255
DUH! ok thx it's late going to bed now lol..