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/*
JavaScript Bible, Fourth Edition
by Danny Goodman
John Wiley & Sons CopyRight 2001
*/
<HTML>
<HEAD>
<TITLE>Number Formatting</TITLE>
<SCRIPT LANGUAGE="JavaScript">
// generic positive number decimal formatting function
function format (expr, decplaces) {
// raise incoming value by power of 10 times the
// number of decimal places; round to an integer; convert to string
var str = "" + Math.round (eval(expr) * Math.pow(10,decplaces))
// pad small value strings with zeros to the left of rounded number
while (str.length <= decplaces) {
str = "0" + str
}
// establish location of decimal point
var decpoint = str.length - decplaces
// assemble final result from: (a) the string up to the position of
// the decimal point; (b) the decimal point; and (c) the balance
// of the string. Return finished product.
return str.substring(0,decpoint) + "." + str.substring(decpoint,str.length);
}
// turn incoming expression into a dollar value
function dollarize (expr) {
return "$" + format(expr,2)
}
</SCRIPT>
</HEAD>
<BODY>
<H1>How to Make Money</H1>
<FORM>
Enter a positive floating-point value or arithmetic expression to be converted to a currency format:<P>
<INPUT TYPE="text" NAME="entry" VALUE="1/3">
<INPUT TYPE="button" VALUE=">Dollars and Cents>"
onClick="this.form.result.value=dollarize(this.form.entry.value)">
<INPUT TYPE="text" NAME="result">
</FORM>
</BODY>
</HTML>
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