// JavaScript Document

function validateFormOnSubmit(theForm) {
	var reason = ""

	reason += validateFirst(theForm.first)
	reason += validateEmail(theForm.email)

	if (reason != "") {
		alert("Some fields are incorrect:\n" + reason)
		return false
	}
	return true
}

function validateFirst(fld) {
	var error = ""

	if (fld.value.length <= 0) {
		fld.style.background = 'Yellow'
		error = "Please enter a name in.\n"
	} else {
		fld.style.background = 'White'
	}
	return error
}

function trim(s) {
	return s.replace(/^\s+|\s+$/, '')
}

function validateEmail(fld) {
	var error = ""
	var tfld = trim(fld.value)	// value of field with whitespace trimmed off
	var emailFilter = /^[^@]+@[^@.]+\.[^@]*\w\w$/ 
	var illegalChars= /[\(\)\<\>\,\;\:\\\"\[\]]/ 
	
	if (fld.value == "") {
		fld.style.background = 'Yellow'
		error = "You didn't enter an email address.\n"
	} else if  (!emailFilter.test(tfld)) {
		fld.style.background = 'Yellow'
		error = "Please enter a valid email address.\n"
	} else if  (fld.value.match(illegalChars)) {
		fld.style.background = 'Yellow'
		error = "The email address contains illegal characters.\n"
	} else {
		fld.style.background = 'White'
	}
	return error
}