Help with preserving image quality when importing to flash!

I am very new with designing, and I would like some help with preserving image quality…i designed the layout in photoshop and all the images are very clear, but when i save them as png’s and import them to flash, i lose quality of the image. Is there another way to import directly to flash…??
Also i would like to create a mask with very fine horizontal lines…and have images passing behind them, like a horizontal pattern over all the images. I have created it in photoshop again using patterns and transparencies, but i do not know how to import it into flash. I know PNG and GIFs support transparencies, but in flash the lines are not recognised…!

Can someone help me pls!