function ValidEmail(obj) {
	// External functions required: TrimString() and FormFocus()
	txtEmail = TrimString(obj.value);
	// if string was trimmed, update the form field value also
	if (txtEmail != obj.value) obj.value = txtEmail;
	flagEmailValid = true;
	atsignIndex = txtEmail.indexOf('@');
	if (txtEmail.length < 5 || atsignIndex < 1 || atsignIndex < txtEmail.lastIndexOf ('@') || txtEmail.indexOf(' ') > -1 || txtEmail.indexOf(',') > -1) {
		flagEmailValid = false;
	}
	else {
		txtDomain = txtEmail.substring(atsignIndex+1,txtEmail.length);
		if (txtDomain.indexOf('.') < 1 || txtDomain.length < 3) {
			flagEmailValid = false;
		}
	}
	if (!flagEmailValid) {
		alert('\n"' + txtEmail + '" is not a valid email address.' + '\n' + '\n' + 'Please enter in the form of username@domain.com' + '\n' + 'or similar format for transmission via the Internet.');
		FormFocus(obj);
	}
	return flagEmailValid;
}