// JavaScript Document
// 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;
}
// performs form verification, 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,
    // then verify that they are numbers and that they are in the right range.
    // Put together error messages for invalid fields.
    for(var i = 0; i < f.length; i++) 
	{
        var e = f.elements[i];
//        if (((e.type == "text") || (e.type == "textarea")) && !e.optional) {
        if (e.type == "text" && !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";
                }
            }
        }
    }
	// check to see if email address field is of valid syntax
	substremail = document.form1.email.value.split("@")
	if (substremail.length > 1)
	{
		index = substremail[1].indexOf(".")
		if (index == -1)
 		{
                    errors += "- please enter a valid e-mail address\n";
		}
	}
	else 
	{
                    errors += "- please enter a valid e-mail address\n";
//		alert("Please enter a valid e-mail address")
//		document.form1.email.focus()
//		return false
	}
    // if there were any errors, display the messages, and
    // return false to prevent the form from being submitted. 

	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;
}