function updateWarning(o,personalised,oldvalue) {
	if (parseInt(o.value)<parseInt(personalised)) { 
		alert('Warning! You are updating this products\'s quantity to '+o.value+' but you have already personalised '+personalised+' items!\nPlease review the personalisation of this product, then try updating the quantity again!');
		o.value = oldvalue;
	}
	return true;
}

function validQty(o) {	
	v = o.value;
    	if (isNaN(v.replace(/ /g,""))) {
    		alert("Please enter a valid quantity!")
    		o.focus();
    	}
}

function isValidQty(o) {	
	v = o.value;
	var returnValue
	if (!isBlank(v)) {
		returnValue = !isNaN(v)
	}	
    	return returnValue
}