It would be good to take time off the read the PHP manual on the basics.
Take a look at the entry for [man]echo/man, for example.
Offhand, I can give 6 different lines that output the same thing, that you want:
echo "<INPUT type=\"text\" name=\"diplom\" value=\"" . $record["Email"] . "\">";
echo "<INPUT type=\"text\" name=\"diplom\" value=\"" . $record['Email'] . "\">";
echo "<INPUT type=\"text\" name=\"diplom\" value=\"{$record["Email"]}"\">";
echo "<INPUT type=\"text\" name=\"diplom\" value=\"{$record['Email']}"\">";
echo '<INPUT type="text" name="diplom" value="' . $record["Email"] . '">';
echo '<INPUT type="text" name="diplom" value="' . $record['Email'] . '">';
You have to look up on strings and arrays to understand.