function valid_form()
{
        if (document.signup_form.SH_Request_Email.value == "")
        {
                alert("Please enter a value for the \"Email\" field.");
        document.signup_form.SH_Request_Email.focus();
        return false;
        }
        if (document.signup_form.SH_Request_Email.value.length < 5)
        {
                alert("Please enter at least 5 characters in the \"Email\" field.");
                document.signup_form.SH_Request_Email.focus();
                return false;
        }
        if (document.signup_form.SH_Request_Email.value.search(' ') > 0)
        {
                alert("Please enter a valid Email address.");
                document.signup_form.SH_Request_Email.focus();
                return false;
        }
}