I tried connecting 2 Cat 2950 switches with a straight cable, ports LED don't light up. Do I need crossover cable for the connection? I am trying to connect one PC to each switch and in vlan 1. Do I need to put the switch into a cluster?

For couple of days I have been trying to set up a flat network between 3 PCs(PC1, PC2& PC3) and the Cisco switch 2950.I was able to ping PC1 running Vista Home OS from PC2(XP Pro) and PC3(vista) but PC1 cannot ping PC2 & PC3. PC2 and PC3 cannot ping ...