// ids of required fields
var required_fields = new Array();

// id => friendly_name mapping of required fields
var friendly_names = new Array();

// alerts user of empty required fields prior to submitting the form
function validate_form() {
	var messages = "";

	num_fields = required_fields.length;
	for (var i = 0; i < num_fields; i++) {
		input_field = document.getElementById(required_fields[i]).value;

		if (input_field.length == 0) {
			if (messages.length > 0)
				messages += ", ";

			messages += friendly_names[required_fields[i]];
		}
	}

	if (messages.length > 0) {
		messages = "The following required fields were left blank:\n" + messages;
		alert(messages);
		return false;
	}
	else {
		return true;
	}
}