function checkform(ov, id)
{
   var p = document.getElementsByName('option[' + id + ']');
   p[0].selectedIndex = ov;
   var q = document.getElementsByName("product[quantity]");
   var qn = 'topt' + ov;
   var qt = document.getElementsByName(qn);
   q[0].value = qt[0].value;
   document.forms['product_form'].submit();
}