new spawntime = GetEventFloat(event,"spawntime");
spawntime should be a float.
if (IsHumanPlayer(client) && IsPlayerGhost && GetClientTeam(client) == 3 && spawntime < 4)
I don't know what IsHumanPlayer does and IsPlayerGhost doesn't look right. Is it a variable or supposed to be a function call? Anyway, here's how I'd write it:
if (client > 0 && client <= MaxClients && IsClientInGame(client) && !IsFakeClient(client) && GetClientTeam(client) == 3 && spawntime < 4.0)