I'm currently using code like this:
    var alphaExp = /^[a-zA-Z]+$/;
    if (f_name.value.length > 1 && f_name.value.match(alphaExp)) {
        // success
    }
    else {
        document.getElementById("f_name_mark").innerText = "<img src='images/icons/cross.png' class='mark'>";
        // fail
    }
However, alphaExp only accounts for upper- and lower-case English characters. How can I allow for foreign letters (é, å, ü etc) and spaces/hyphens?
 
     
    