function ValidateFriendsEmails()
{
    if (!ValidateRegEx("^[-_a-zA-Z0-9][-_.a-zA-Z0-9]*@[-.a-zA-Z0-9]+(\.[-.a-zA-Z0-9]+)*\.(com|edu|info|gov|int|mil|net|org|biz|name|museum|coop|aero|pro|tv|[a-zA-Z]{2})$", document.getElementById("email").value))  
    {
        document.getElementById("divError").innerHTML = "<br />Your email address is not valid.";
        document.getElementById("divError").style.display = "";
        return false;        
    }
    
    for (var i=1; i<6; i++)
    {
        if (document.getElementById("friend" + i + "name").value.length > 0)
        {
            if (!ValidateRegEx("^[-_a-zA-Z0-9][-_.a-zA-Z0-9]*@[-.a-zA-Z0-9]+(\.[-.a-zA-Z0-9]+)*\.(com|edu|info|gov|int|mil|net|org|biz|name|museum|coop|aero|pro|tv|[a-zA-Z]{2})$", document.getElementById("friend" + i + "email").value))
            {
                document.getElementById("divError").innerHTML = "<br />Friend " + i + "'s email address is not valid.";
                document.getElementById("divError").style.display = "";
                return false;
            }
        }
    }

    document.getElementById("divError").style.display = "none";
    return true;        
}

function ValidateRegEx(expression, value) 
{
    var objRegExp = new RegExp(expression);
    return objRegExp.test(value);
}

function newWindow() 
{
    previewWindow = window.open('preview.html', 'Preview', 'width=600, height=350, scrollbars=yes')
}

function limitText(limitNum) 
{
    var limitField = document.getElementById("ttMessageCustomMessage");
    var limitCount = document.getElementById("countDownReminder");
    if (limitField.value.length > limitNum) {
        limitField.value = limitField.value.substring(0, limitNum);
    }
    var charLeft = limitNum - limitField.value.length;
    limitCount.innerHTML = "<font size='1'>You have " + charLeft + " characters left</font>";
}