Queries :: Find The Recent Available Data Based On Dates?

I have a price table:

Code:
tblPrice
PosNr PriceDate Company Price
1 01.01.2014 Firma A 5
2 02.01.2014 Firma A 7
3 03.01.2014 Firma A 9
4 04.01.2014 Firma A 8
5 06.01.2014 Firma A 6
6 02.01.2014 Firma XY 11
7 03.01.2014 Firma XY 9
8 04.01.2014 Firma XY 7
9 05.01.2014 Firma XY 8
10 06.01.2014 Firma XY 10

And I have a table with the dates, for which I need a price.

Code:
tblDates
PosNr PriceDate Company
1 01.01.2014 Firma A
2 02.01.2014 Firma A
3 03.01.2014 Firma A
4 04.01.2014 Firma A
5 05.01.2014 Firma A (no price available)
6 06.01.2014 Firma A
7 02.01.2014 Firma XY
8 03.01.2014 Firma XY
9 04.01.2014 Firma XY
10 05.01.2014 Firma XY
11 06.01.2014 Firma XY

And now I want to combine this tables, and for the dates which have no price, the last price should be taken.

Code:
tblResult
PosNr PriceDate Company Price
1 01.01.2014 Firma A 5
2 02.01.2014 Firma A 7
3 03.01.2014 Firma A 9
4 04.01.2014 Firma A 8
5 05.01.2014 Firma A 8 (actualy no priceavailable, so take last price)
6 06.01.2014 Firma A 6
7 02.01.2014 Firma XY 11
8 03.01.2014 Firma XY 9
9 04.01.2014 Firma XY 7
10 05.01.2014 Firma XY 8
11 06.01.2014 Firma XY 10

how I can get this?

I have this code, but it need hours.

Code:
SELECT tblDates.PosNr, tblDates.Company, tblDates.PriceDate, (SELECT TOP 1
B.Price
FROM
tblPrices As B
WHERE
B.Company = tblDates.Company
AND
B.PriceDate <= tblDates.PriceDate
ORDER BY
B.PriceDates DESC ) AS Price
FROM tblPrices RIGHT JOIN tblDates ON (tblPrices.PriceDate = tblDates.PriceDates) AND (tblPrices.Company = tblDates.Company);