[ZP] First Zombie Freeze

Guys Please Help?
#include <amxmodx>
#include <fun>
#include <zombieplague>

#define PLUGIN "[ZP] Freeze Nemesis"
#define VERSION "1.0"
#define AUTHOR "wicho"

#define MarkPlayerSpeed(%0) bitPlayerSpeed |= (1 << (%0 & 31))
#define ClearPlayerSpeed(%0) bitPlayerSpeed &= ~(1 << (%0 & 31))
#define IsPlayerSpeed(%0) bitPlayerSpeed & (1 << (%0 & 31))

new bitPlayerSpeed

new cvar_time

public plugin_init()
{
register_plugin(PLUGIN, VERSION, AUTHOR)

cvar_time = register_cvar("zp_freeze_frost_zombie", "5.0")
}

public zp_user_infected_post(id, infector, nemesis)
{
if(is_user_alive(id) && zp_get_user_first_zombie(id))
{
IsPlayerSpeed(id) = get_user_maxspeed(id)
set_user_maxspeed(id, 1.0)
set_task(cvar_time, "Unfreeze", id)
}
}

public Unfreeze(id)
{
set_user_maxspeed(id, IsPlayerSpeed(id))
}