Add product with attributes from non-miva site

[tleah1]

Hi,
We would like to add the products to the basket from our website that is not the miva store. I can add them using this form, but once I try to add in the attributes I get sent to the page

• Missing Product Attributes

Attributes in bold are required.

Is it possible to add products with attributes to the basket like this, or is there another way to do it?

<form action="http://cartdataq.mivamerchant.net/mm5/merchant.mvc?" method="post" class="product-form" novalidate>

<input type="hidden" name="Old_Screen" value="PROD" />
<input type="hidden" name="Old_Search" value="" />
<input type="hidden" name="Action" value="ADPR" />
<input type="hidden" name="Screen" value="BASK" />
<input type="hidden" name="Attributes" value="Yes" />
<input type="hidden" name="Store_Code" value="cartdataq" />
<input type="hidden" name="Product_Code" value="CAL-EL-USB-TEMP-1" />
<input type="hidden" name="Category_Code" value="" />
<input type="hidden" name="Offset" value="" />
<input type="hidden" name="AllOffset" value="" />
<input type="hidden" name="CatListingOffset" value="" />
<input type="hidden" name="RelatedOffset" value="" />
<input type="hidden" name="SearchOffset" value="" />
<input type="hidden" name="Current_Product_Code" value="CAL-EL-USB-TEMP-1" />

<input type="hidden" name="Product_Attributes[1]:code" value="CALCert" />

<select name="Product_Attributes[1]:value">
<option value="CAL1">-8°C / 17°F</option>
<option value="CAL2">0°C / 32°F</option>
</select>

<label for="prod-qty">Quantity:</label>
<input type="text" name="Quantity" value="1"/>
<input type="submit" value="Add to Cart" title="Add to Cart" id="add-to-cart" class="button button-large add-to-cart" />
</form>