When to make a class

My background is in Object Oriented Pascal (Delphi), however I am having difficulty knowing when to make a class in PHP. For instance, in my script file, functions.php, I have these functions among others: /* Input a field */ function input_field($name, $value, $size, $max) {

    echo('<INPUT TYPE="text" NAME="' . $name . '" VALUE="' . $value .
         '" SIZE="' . $size . '" MAXLENGTH="' . $max . '">');

}; /* Input a password field */ function input_password_field($name, $value, $size, $max) {

    echo('<INPUT TYPE="password" NAME="' . $name . '" VALUE="' . $value .
         '" SIZE="' . $size . '" MAXLENGTH="' . $max . '">');

}; Should I have a class that contains these functions (methods)? One of my non-profit clients would like to have an online emailer program driven by a MySQL database. This I can envision as a class, actually several classes (e.g. send mail, create message, select addresses, etc.). Todd