function isValidEmail(str) {
   return (str.indexOf(".") > 2) && (str.indexOf("@") > 0);
}

function isValidPositiveInteger(inpString) {
   return /^\d+$/.test(trim(inpString));
}

function isValid3Digits(inpString) {
	return /^\d{3}$/.test(trim(inpString));
}

function isValid4Digits(inpString) {
	return /^\d{4}$/.test(trim(inpString));
}


function verify_subscribe_email() {
	$valid = isValidEmail(document.form_subscribe.subscribe_email.value);
	
	if (!$valid) { alert("Please enter your email address"); }
	return $valid;
}

function do_submit_subscribe() {

	if (!verify_subscribe_email()) return false;
	document.form_subscribe.submit();	
}

/* String utilities */
function ltrim(str) { 
	for(var k = 0; k < str.length && isWhitespace(str.charAt(k)); k++);
	return str.substring(k, str.length);
}
function rtrim(str) {
	for(var j=str.length-1; j>=0 && isWhitespace(str.charAt(j)) ; j--) ;
	return str.substring(0,j+1);
}
function trim(str) {
	return ltrim(rtrim(str));
}
function isWhitespace(charToCheck) {
	var whitespaceChars = " \t\n\r\f";
	return (whitespaceChars.indexOf(charToCheck) != -1);
}