ID:171535
 
When u r a alien u get warped to the marine base(enemies) and if u r a soldier r just teleported to your base....
    Death(mob/M.)
if(M.hp == 0)
world<<"<font color=blue>[M.key] has been killed by [usr.key]"
usr.kills += 1
M.deaths +=1
if(M.alien ==1)
M.loc=locate(22,22,3)
if(M.soldier ==1)
M.loc=locate(41,41,5)
for(var/obj/healthbar/H in M.client.screen)
take away the period after mob/M and try else if
Your first problem is that you're using usr in your proc. Your second problem is that you're using two variables where one will suffice (if they are always defined by each other, for example, if alien is 1, soldier is 0, then they should just be one variable, with 1 representing alien, and 0 representing soldier).
And dont use if hp==0, what if the hp was below 0 due to a big attack? Unless you put in your atack code to never drop the hp below 0, the hp wont always be excatly 0 when the person needs to die. Which is why you should do if(M.hp<=0)