I have an input in my form like this:
<div>
    <label for="phone">Phone Number:</label> <br />
    <input type="text" id="phone" name="phone" /> <br />
    <span id="phoneInfo" style="font-size: 11px;color:red;"></span>
</div>
and I want limit characters on this input and here is javascript code
var phone = $("#phone");
var phoneInfo = $("#phoneInfo");
function validatePhone(){
    var a = $("#phone").val();
    var filter = /^[0-9]$/;
    //it's valid
    if(filter.test(a) || message.val().length > 10){            
        phone.removeClass("error");
        phoneInfo.text("- thank you");
        phoneInfo.removeClass("error");
        return true;
    }
    //it's NOT valid
    else{
        phone.addClass("error");
        phoneInfo.text("X");
        phoneInfo.addClass("error");
        return false;
    }
}
but it doesn't work...
 
     
     
     
    