You can't do what you describe with a standard textarea or input of type='text'.
These are input forms that do not provide for internal styles: they allow only for a single style for the entire area. You can manage the overall style using style= commands or javascript.
What you are describing is a 'rich text' area. There are several of these floating around as shareware or cheapware. You can find them by googling or searching the usual shareware sites for PHP freaks.
So far as I know, they only work in IE 5.5 or better for PCs only. Not Mac IE, not Netscape, not Phoenix. I don't know about Opera but I doubt it.
If you use a 'rich text' area there will be instructions (if you're lucky) or javascript code at the very least that describe how the area is programmed to capture italics in text. Typically it's done by bracketing the displayed text with HTML commands. For this sort of situation, you'd simply capture and save the whole styled text.
If for some reason you want to separately save the italicized word(s), you'd have to parse for the HTML the rich text area used. Some might say '<i>text</i>'; others <span style='text-style:italic'>text</span>, etc. You'll have to deconstruct the javascript to figure out what to parse to find your italic word.
GOOD LUCK!
