GeSHi (python):
def smokegrenade_detonate(ev):
    # this will call out the below every time a smoke grenade is detonated.
    userid = ev['userid']
    # named ev['userid'] to userid for quicker reference.
    attacker = ev['attacker']
    # named ev['attacker'] to attacker for quicker reference.
    x = event_var(x)
    # the x coordinate of the smoke grenade detonation location.
    y = event_var(y)
    # the y coordinate of the smoke grenade detonation location.
    z = event_var(z)
    # the z coordinate of the smoke grenade detonation location.
    command = wcs.Command(userid)
    # just named it for easier reference.
    if ev['es_userteam'] == 2:
        filtername = '#ct'
    else:
        filtername = '#t'
# gets the enemy team and stores it as "filtername' (note: if ev['es_userteam'] == 2 then that team is the terrorist, if it == 3 then its the counter-terrorist, if it == 1, the its specs.
    while playerlib.nearCoord((x, y, z), 50, filtername):
    # while is a loop command in python.   playerlib = is a ESP() module which can be used for MANY things.    .nearCoord = a ESP() module command that gets a list of players within a specifed area.     x = event_var(x), the x coordinate of the smoke grenade detonation.    y = event_var(y), the y coordinate of the smoke grenade detonation.     z = event_var(z), the z coordinate of the smoke grenade detonation.  (side note: when x, y, and z are next to each other like this, we call it a vector also known as the location coord's).    50 = diameter from the "vector" and out,  to check for players entering the smoke.    filtername = a filtername is a value we have to "filter" playernames out of the playerlist (note: playerlib.nearCoord is a list of all players in the diameter of 50 in-game units of vector. in this case filter is = to the opposite of your team so that it hurts the other team, not your team.
        command.Damage( 1, 131072, attacker)
        # command = wcs.Command (a name used to call out a WCS Python Command).  .Damage( The WCS Python Command were calling out).    1 = damage, (since the python loop module "while" loops very quick, setting it to one will drain his health at a better rate).    131072 = the type of damage being done (its just extra, its not actually neccesary).    attacker = the attacker who actually threw the smoke grenade in the first place.[code]
 
well I hope this helped you out at atleast i little bit. :D
    Best of luck,
        -Dan-