12.3. format-number(): Convert a number to a string

This function takes two required arguments and a third optional argument:

    format-number(n, p [,f])

where:

`n`	is the number to be formatted
`p`	is a format pattern string using the characters described below
`f`	if supplied, this is the name of a named `<xsl:decimal>` format item that will be used to determine internationalization features of the formatting, such as the grouping separator.

Here are the characters used in the formatting pattern p:

Table 1. Format pattern characters for format-number()

`#`	Denotes a digit. Leading and trailing zeroes (and a trailing decimal, if any) will disappear.
`0`	Denotes a digit, but a digit always appears, even if it is a zero.
`-`	Shows the position of the minus sign.
`.`	Shows the position of the decimal point.
`,`	Positions the grouping separator for thousands. For example, `"##,###.00"`.
`%`	Multiplies the number by one hundred and displays it as a percentage.
`;`	You can supply two patterns separated by a semicolon; the first one will be used for positive numbers and the second for negative numbers.
other	Literal characters are carried through to the result.

XSLT Reference