function validate(myForm) 
{
    var error = null;

    for (var i = 0; i < myForm.elements.length; i++) {
        var input = myForm.elements[i];

        if (input.value == "") {
            if (error == null) {
                error = "please enter a value for " + input.title;
                input.focus();
            }
            else {
                error += "\nplease enter a value for " + input.title;
            }
        }
    }

    if (error == null) {
        var input = document.getElementById("emailAddress");

        if (!(/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(input.value))) {
            error = "email format incorrect";
            input.focus();
        }
    }

    if (error != null) {
        alert(error);
    }

    return error == null;
}