Suggested Solution to HW #6 CSCI 5931, Fall 2000

CSCI 4230
Internet Applicaiton Development
Fall 2000
Suugested Solution to Homework #6

(1) For example:

<html>
<head>
<script language="JavaScript">
<!-- Hide from JavaScript-Impaired Browsers
function isDigit(c) {
return ((c >= "0") && (c <= "9"));
}

function isFloat(s){
      var i;
   var decimalEncountered = false;
      for (i = 0; i < s.length; i++) {
          if (!isDigit(s.charAt(i)) && (s.charAt(i) != '.')) return false;
    if (decimalEncountered && s.charAt(i) == '.') return false;
    if (s.charAt(i) == '.') decimalEncountered = true;
      }
   return true;
}

function showSquare(f, s) {
   if (s == '') {
   f.square.value = "";
   return;
   }
   if (!isFloat(s))
       f.square.value = "Sorry, " + s + " is not a decimal number."
   else {
      val = parseFloat(s);
   f.square.value = val * val;
   }
}

// End Hiding -->
</script>
</head>
<body bgcolor="#ccccff">
<h2>Get the square of a number</h2>
<form onSubmit="showSquare(this, this.number.value); return false;">
Please input a non-negative decimal number:
<input type="text" NAME="number" size="40" value=""
onChange="showSquare(this.form, this.value);"><br>
Result Square: <input type="txt" name="square" size="40">
<br>
<input type="submit" value="Get Square!">
</body>
</html>