How to update date in mysql -

my code looks this

<?php $con = mysql_connect("localhost","root",""); if (!$con) { die('could not connect: ' . mysql_error()); } mysql_select_db("library", $con);  $colid = $_post['data']; $count = count($colid); $curdate = date('y-m-d'); for($i=0;$i<$count;$i++){  $tsql ="update transaction         set return=$curdate        status='1'        tid = $colid[$i] ";  $tresult = mysql_query($tsql); } if(! $tresult ) { die('could not enter data: ' . mysql_error()); } echo "deleted book successfully\n"; mysql_close($con);  ?> 

and error

could not enter data: have error in sql syntax; check manual corresponds mysql server version right syntax use near 'return=2014-04-21 status='1' tid = 1' @ line 2 

my requirement when ever got clicked button need execute code

i tried using curdate() function getting same error

any appreciated

return mysql reserved keyword need wrap back-ticks,and missing comma before status pointed @user3414693

update transaction         set `return`=curdate(),        status='1'        tid = $colid[$i]