Problems editing image/font

I am using a font to place a heading on my webpage. I'm trying to create my heading in photoshop because visitors won't have the font I am using.

My font has some white in it, I save as a .gif with a transparent background, when I view it on the page the background shows in the white spots inside the letters. I want to edit the image to place white in these spots but keep the transparent background, If I flatten the image the transparent background no longer exists.

BTW I am using Photoshop 5

Try making the background (that will become transparent) a color that isn't used in the image. Then, when youmake that color transparent, the white will remain. I would choose a color close to whatever color the website background is so you don't end up with a color halo.