// 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;
}
// 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;
}
// 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;
}
You are being directed to our new home page, please Click Here for immediate connection.
