[Zeromanster]

On top of the script:

pawn Код:

forward CheckPlayerPos(playerid);

Under OnGameModeInit:

pawn Код:

SetTimer("CheckPlayerPos", 3000, 1);

At the end of your script:

pawn Код:

public CheckPlayerPos(playerid)
{
  IsPlayerInRangeOfPoint(playerid, Float:range, Float:x, Float:y, Float:z)
  {
    // The DialogShow code here.
  }
  return 1;
}