PHP passing data using form -

i have form passes data index.php update.php. code passed date of birth variable didn't pass $leadid variable. wrong code?

part of code in index.php

<form method="post" action="update.php"> <table width="400" border="0" cellspacing="1" cellpadding="2">  <tr> <td width="100">lead id</td> <td> <?php  mysql_connect('localhost', 'root', ''); mysql_select_db('test');  $sql = "select leadid table lead_no ='$lead_no'"; $result = mysql_query($sql); $row = mysql_fetch_row($result); $leadid = $row[0];  echo $leadid;  ?> </td> </tr>  <tr> <td width="100">date of birth</td> <td><input name="birth" type="date" id="birth"></td> </tr> </table> </form> 

in update.php have post

 $id = $_post['leadid'];  $birth = $_post['birth']; 

in code there no input field leadid variable. try adding hidden field this:

<input type="hidden" value="<?php echo $leadid;?>" name="leadid" /> 

then, post variable should transferred.