Function to detect and match a user agent string

user-agent-match.js

function detectFromUserAgentString(stringToMatch) {
    var userAgentString = navigator.userAgent.toLowerCase(),
        result;
    if (userAgentString.search(stringToMatch) > -1) {
        result = true;
    } else {
        result = false;
    }
    return result;
}

detectFromUserAgentString('iPhone');