intervlan routing with Netgear GSM7312 and GSM7248

This is what I have
Firewall (ISA) connected to GSM 7312(layer 3 switch)
On GSM 7312(layer 3 switch):
Port1 ? 192.168.50.1 connected to firewall
Port 2 ? 192.168.60.1 connected to a 5 port Linksys switch
Port 3 ? 192.168.59.1 connected to a 5 port Linksys switch
Port 4 ? 192.168.0.1 connected to a 5 port Linksys switch

I want to get rid of those 5 port switches. I got a layer 2 switch GSM7248 which I want to connect it to the GSM7312 and create vlan on GSM7312

Thank You