I am trying to select data from a MySQL table, but I get one of the following error messages:
mysql_fetch_array() expects parameter 1 to be resource,
Try this, it must be work, otherwise you need to print the error to specify your problem
$username = $_POST['username'];
$password = $_POST['password'];
$sql = "SELECT * from Users WHERE UserName LIKE '$username'";
$result = mysql_query($sql,$con);
while($row = mysql_fetch_array($result))
{
echo $row['FirstName'];
}