new box; //on top of your gm under includes
if (!strcmp("/createbox", cmdtext, true, 10))
{
   new Float:x,Float:y,Float:z;
   GetPlayerPos(playerid,x,y,z);
   box = CreateObject(1220,x,y,z,0,0,0);
    return 1;
}
if (!strcmp("/removebox", cmdtext, true, 10))
{
   DestroyObject(box); 
    return 1;
}