Someone

on *:TEXT:@world *:#: {
   if ($2 == $null) { msg $chan 4Enter a channel please $nick}
   else { /msg $chan $chan($2).topic 
}
 }
on *:TEXT:!world *:#: {
  if ($2 == $null) { msg $nick 4Enter a channel please $nick }  
else { /msg $nick $chan($2).topic }
}