Explode, Arrays and Checkboxes

I'm not new to PHP, but I have very little experience with arrays. I have comma separated values in a database, that I need to pull out, explode into an array, then check certain checkboxes if they exist. I have two variables: $x = "2,10,34" $y = "28,15,16" I need to explode them both, so that the values of $x are they keys, and the values of $y are the values. Is that possible? I have a form, with checkboxes that are named $product[1] through [40]. Next to them are textboxes labeled $price[1] through [40]. How would make the form, when it loads, have $product[2], [10], [34] checked, with $price[2], [10], and [34] equal to "28", "15", and "16" respecively. Any help would be greatly appreciated. -- Matt Winslow matt@mattwinslow.com