[arnutisz]

create a variable, like:

pawn Code:

new bool:textdrawon[MAX_PLAYERS];

OnPlayerConnect add:

pawn Code:

textdrawon[playerid] = false;

Then in your command add:

pawn Code:

if(textdrawon[playerid] == false)
{
  TextDrawShowForPlayer(...);
  textdrawon[playerid] = true;
}
else if(textdrawon[playerid] == true)
{
  TextDrawHideForPlayer(....);
  textdrawon[playerid] = false;
}