function filter(str) {
    searchString = str.toLowerCase();
    contactList = getElementsByClassName(document.getElementById("contact"), "div", "contact_name");
    contactListPhones = getElementsByClassName(document.getElementById("contact"), "div", "contact_phone");
    styleName = " hideIt";
        for (var i = 0; i < contactList.length; i++) {
        // if the contact's name contains the searchString
        content = contactList[i].innerHTML.toLowerCase();
        content = content.substring(content.search(">")+1,content.search("</"));
        contentPhone = contactListPhones[i].innerHTML.toLowerCase();
        if (content.match(searchString) == searchString || contentPhone.match(searchString) == searchString) {
            grandParentNode = contactList[i].parentNode.parentNode;
            grandParentNode.className = grandParentNode.className.replace(styleName, "");
        } else {
            grandParentNode = contactList[i].parentNode.parentNode;
            if (grandParentNode.className.match(styleName) != styleName) {
                grandParentNode.className = grandParentNode.className + styleName;
            }
        }
    }
        return true;
}