How to join two tables in mysql?

<?php
// Simple Join Query
mysql_connect("localhost", "root", "pass") or die(mysql_error());
mysql_select_db("dbname") or die(mysql_error());

$query = "SELECT emp.empname, empdesig.designation FROM emp, empdesig WHERE emp.empname = empdesig.empname";
   
$result = mysql_query($query) or die(mysql_error());

//display record empname with designation.

while($rec = mysql_fetch_array($result))
   {
    echo $rec['empname']. " :- ". $rec['designation']."<br>";
    }
?>