Easy way to add drop down menu with 1 - 100 without doing 100 different options?

Not with plain HTML I'm afraid.

You could use some jQuery to do this though:

$(function(){
    var $select = $(".1-100");
    for (i=1;i<=100;i++){
        $select.append($('<option></option>').val(i).html(i))
    }
});​

-- SEE DEMO --

You can download jQuery here

Are you using JavaScript or jQuery besides the html? If you are, you can do something like:

HTML:

<select id='some_selector'></select>​

jQuery:

var select = '';
for (i=1;i<=100;i++){
    select += '<option val=' + i + '>' + i + '</option>';
}
$('#some_selector').html(select);

As you can see here.

Another option for compatible browsers instead of select, you can use is HTML5's input type=number:

<input type="number" min="1" max="100" value="1">

Not with pure HTML as far as I know.

But with JS or PHP or another scripting language such as JSP, you can do it very easily with a for loop.

Example in PHP:

<select>
<?php
    for ($i=1; $i<=100; $i++)
    {
        ?>
            <option value="<?php echo $i;?>"><?php echo $i;?></option>
        <?php
    }
?>
</select>