// A utility function that returns true if a string contains only
// whitespace characters.
function isblank(s) {
    for(var i = 0; i < s.length; i++) {
        var c = s.charAt(i);
        if ((c != ' ') && (c != '\n') && (c != '\t')) return false;
    }
    return true;
}

function isEmail(str) {
  // are regular expressions supported?
  var supported = 0;
  if (window.RegExp) {
    var tempStr = "a";
    var tempReg = new RegExp(tempStr);
    if (tempReg.test(tempStr)) supported = 1;
  }
  if (!supported)
    return (str.indexOf(".") > 2) && (str.indexOf("@") > 0);
  var r1 = new RegExp("(@.*@)|(\\.\\.)|(@\\.)|(^\\.)");
  var r2 = new RegExp("^.+\\@(\\[?)[a-zA-Z0-9\\-\\.]+\\.([a-zA-Z]{2,3}|[0-9]{1,3})(\\]?)$");
  return (!r1.test(str) && r2.test(str));
}
// This is the function that performs form verification. It is invoked
// from the onsubmit event handler. The handler should return whatever
// value this function returns.
function verify(f) {
    var msg;
    var empty_fields = "";
    var errors = "";

    // Loop through the elements of the form, looking for all
    // text and textarea elements that don't have an "optional" property
    // defined. Then, check for fields that are empty and make a list of them.
    // Also, if any of these elements have a "min" or a "max" property defined,
    // verify that they are numbers and in the right range.
    // If the element has a "numeric" property defined, verify that
    // it is a number, but don't check its range.
    // Put together error messages for fields that are wrong.

    for(var i = 0; i < f.length; i++)
    {
        var e = f.elements[i];
        if (((e.type == "text") || (e.type == "textarea")) && !e.optional)
	{
            // first check if the field is empty
            if ((e.value == null) || (e.value == "") || isblank(e.value))
            {
                empty_fields += "\n          " + e.name;
                continue;
            }
	    if (e.validCharsOnly)
	    {
	    	result = e.value.search(/[.]?[\W]+/g);
	    	if (result > -1)
	    	{
		    alert("\n          Illegal Character in Account!");
		    return false;
		}
	    }
	    if (e.validEmailOnly)
	    {
		if(!isEmail(e.value))
	    	{
		    alert("\n          Your email address appears to be invalid!");
		    return false;
		}

            }
            // Now check for fields that are supposed to be numeric.
            if (e.numeric || (e.min != null) || (e.max != null))
            {
                var v = parseFloat(e.value);
                if (isNaN(v) ||
                    ((e.min != null) && (v < e.min)) ||
                    ((e.max != null) && (v > e.max)))
                {
                    errors += "- The field " + e.name + " must be a number";
                    if (e.min != null)
                        errors += " that is greater than " + e.min;
                    if (e.max != null && e.min != null)
                        errors += " and less than " + e.max;
                    else if (e.max != null)
                        errors += " that is less than " + e.max;
                    errors += ".\n";
                }
             }
          }
     }

    // Now, if there were any errors, display the messages, and
    // return false to prevent the form from being submitted.
    // Otherwise return true.
    if (!empty_fields && !errors)
    {
	return true;
    }
    msg  = "______________________________________________________\n\n"
    msg += "The form was not submitted because of the following error(s).\n";
    msg += "Please correct these error(s) and re-submit.\n";
    msg += "______________________________________________________\n\n"

    if (empty_fields) {
        msg += "- The following required field(s) are empty:"
                + empty_fields + "\n";
        if (errors) msg += "\n";
    }
    msg += errors;
    alert(msg);
    return false;
}