Virtuemart 1.1.9 Hack fro product child search

Virtuemart 1.1.9 Joomla 1.5.17 Modify the [login to view URL], [login to view URL],[login to view URL] Create a drop down list next to "order by"(price,name etc that the virtuemart all ready have) with the attribute names from the child products from the category. The child products have an attribute names from the size (Medium,Large etc) when i am in a category and this category has products with child products then a dropdown list has appears next to "order by" with the names of attributes that this category has from the child products. For exaple if we are in T-shirt category a drop down menu with size (small, medium, large, xl-large) if we are in shoes a drop down with attributes(36,37,38.5 etc) and when i pick one of this then i want to show me the products that they have a child with this attribute and this child product have a stock and the parent are publish.