<?php

$getresult = mysql_query("SELECT * FROM users WHERE uid=$uid")
or die(mysql_error());

$row = mysql_fetch_array($getresult);

$vitimas1 = $row['vitimas'];

$vitimas2 = "VARIAVEL QUE VAI ADICIONAR NA TABELA (JSESSIONI)";

$result = mysql_query("UPDATE users SET vitimas=$vitimas.','.$vitimas2 WHERE uid=$uid")
or die(mysql_error());

?>