function preload() {
    var args = preload.arguments;
    document.imageArray = new Array(args.length);
    for(var i=0; i<args.length; i++) {
            document.imageArray[i] = new Image;
            document.imageArray[i].src = args[i];
    }
}

function is_blank(s) {
    for(var i = 0; i < s.length; i++) {
        var c = s.charAt(i);
        if ((c != ' ') && (c != '\n') && (c != '\t')) return false;
    }
    return true;
}

function emailInputFocus(input, id) {
    if(input.value == "Your email address") {
        input.value = "";
    }
    document.getElementById(id).className = "mailingListFocus";
}

function emailInputBlur(input, id) {
    if((input.value == "") || is_blank(input.value)) {
        input.value = "Your email address";
        document.getElementById(id).className = "mailingListBlur";
    }
}

function valid_email(e) {
    var validChars = "1234567890qwertyuiop[]asdfghjklzxcvbnm.@-_QWERTYUIOPASDFGHJKLZXCVBNM";

    for(i=0; i < e.length ;i++){
        if(validChars.indexOf(e.charAt(i))<0){
            return false;
        }
    }


    re = /(@.*@)|(\.\.)|(^\.)|(^@)|(@$)|(\.$)|(@\.)/;
    re_two = /^.+\@(\[?)[a-zA-Z0-9\-\.]+\.([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$/;
    if (!e.match(re) && e.match(re_two)) {
        return (-1);
    }
}

function checkMailSubscription(form) {
        if(!valid_email(form.email.value)){
            alert("Invalid email address.");
            return false;
	}

	return true;
}

function swapImage(n,src) {
    if (document.images) {
            document[n].src = src;
    }
}