Filtering Entries Within Bounds

I have a cost field and I would like to be able to filter the results based on a simple 2 field search form where the user can set the minimum and maximum price, how would I restrict the results so that only the correct items are shown?

At the moment there is less than and more than options in the filters, but this doesn't work because the user sets a min price and a max price and the because the less than allows any results that are less than the max value.

Perhaps I am missing something obvious but I've been round in circles with this for a little while now and I am not seeing it, anyone any clues?

Thanks

Steve