Replace Quantity drop down to text input box. 4.0+ with buy

<SELECT id="product_avail" name="amount"{if $active_modules.Product_Options ne '' && $product_options ne ''} onchange="check_wholesale(this.value);"{/if}>
{section name=quantity loop=$mq start=$start_quantity}
<OPTION value="{%quantity.index%}" {if $smarty.get.quantity eq %quantity.index%}selected{/if}>{%quantity.index%}</OPTION>
{/section}
</SELECT>

<input type="text" name="amount" size="3" value="1">  

<SELECT name="amount">
{if $product.min_amount le 1}
{assign var="start_quantity" value=1}
{else}
{assign var="start_quantity" value=$product.min_amount}
{/if}
{section name=quantity loop=$mq start=$start_quantity}
<OPTION value="{%quantity.index%}" {if $smarty.get.quantity eq %quantity.index%}selected{/if}>{%quantity.index%}</OPTION>
{/section}
</SELECT>