hi!i have created a contact form using c# and web services.i would like to get an alert message if the user hasnt filled his name or when his name is a number.this is my c# code:

public partial class Default2 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        Validation.WebService validate = new Validation.WebService();
        bool ismail = validate.isEmail(TextBox2.Text);
        if (!ismail)
          { Label1.Text = "your mail is wrong!!"; }

        Validation.nameVal valid = new Validation.nameVal();
        bool isname = valid.isName(TextBox1.Text);
        if (!isname )
        { Label2.Text = "Your name is wrong!!"; }

        else if (isname==null)
        { Label2.Text = "Please fill in your name"; }

        if (isname && ismail)
        {  
            { Label1.Text = null; Label2.Text = null;
            Label3.Text = "Your message has been send!";}
            }
        }
}

with this code i have a null exception..