And remember that with bindparam(), you don't want to have quotes around the parameter, because they're added for you:
$strcon= $dbconn->prepare("SELECT employee_name
FROM employee where employee_name LIKE ?");
$strconn->bindParam(1,'%' . $querysearch . '%');
If that doesn't help, show more code AND define "doesn't work" with a bit more detail please - do you get errors, or does it just not return anything?