[woodscooter]

Hello dog,

You are nearly there, but not quite.

$salt = 'xyz'; You are showing leading and trailing spaces. Can't do that.
I assume you have found the correct salt from looking at the database.

$hash=MD5(MD5($password) . $salt); Concatenate the strings with a dot, not a +

$update_profile = "UPDATE user
SET password='$hash'
WHERE userid=99";

your '".$hash."' has way too many quotes and dots

your ' *My User ID* ' has spaces and does not need quotes if it's a plain number.

I have tried that query myself and I can assure you it works.