<?php 

$query = mysql_query("SELECT count(*) FROM $tb1 ") or die(mysql_error());



$nb_entrees = mysql_result($query,0,0);





mysql_close();



 if($nb_entrees <= 10)

  {

   $pos_X=rand(0,10);

   $pos_Y=rand(0,10);

  }

 elseif($nb_entrees > 10 &  $nb_entrees < 50)

  {

   $pos_X=rand(-10,0);

   $pos_Y=rand(-10,0);

  }

 elseif($nb_entrees > 50 &  $nb_entrees < 300)

  {

   $pos_X=rand(10,50);

   $pos_Y=rand(10,50);

  }

 elseif($nb_entrees > 300 &  $nb_entrees < 650)

  {

   $pos_X=rand(-10,-50);

   $pos_Y=rand(-10,-50);

  }

..................