//
// Common Javascript Functions
// Copyright 2000 Deep Thought Consultants Ltd
//
function ucFirst(s)
{
	var c = s.charAt(0);

	if (parseInt(s.length)==1){
		return c.toUpperCase();
	}
	else
	{
		return c.toUpperCase() + s.slice(1).toLowerCase();
	}
}

// validate an email address
function isValidEmail(e)
{
	// assume an email address cannot start with an @ or white space, but it
	// must contain the @ character followed by groups of alphanumerics and '-'
	// followed by the dot character '.'
	// It must end with 2 or 3 alphanumerics.
	//
	var alnum="a-zA-Z0-9";
	exp="^[^@\\s]+@(["+alnum+"+\\-]+\\.)+["+alnum+"]["+alnum+"]["+alnum+"]?$";
	emailregexp = new RegExp(exp);

	result = e.match(emailregexp);
	if (result != null)
	{
		return true
	}
	else
	{
		return false;
	}
}

// checks whether a field is empty
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 will be 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 = "";
    var mylen = parseInt(f.length);

    // 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,
    // then verify that they are numbers and that they are in the right range.
    // Put together error messages for fields that are wrong.
    for(var i = 0; i < mylen; 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          " + ucFirst(e.name);
                continue;
            }

	    // now validate email addresses
	    if (e.email) {
		if (!isValidEmail(e.value)) {
			errors += "Invalid email address\n"}
		}
	
            // 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 " + ucFirst(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, then display the messages, and
    // return true to prevent the form from being submitted.  Otherwise
    // return false
    if (!empty_fields && !errors) return true;

    msg  = "Sorry, but we cannot process your request because of the\n";
    msg += "following error(s). Please correct the problem and try again\n\n";

    if (empty_fields) {
        msg += "- The following fields are mandatory:" 
                + empty_fields + "\n";
        if (errors) msg += "\n";
    }
    msg += errors;
    alert(msg);
    return false;
}