function check_field() {
    if(    document.forms.new_blog.name.value.length > 0 &&
        document.forms.new_blog.title.value.length > 0 &&
        document.forms.new_blog.email.value.length > 0) {
        document.forms.new_blog.submit.disabled = false;
    }
}

function check_field2() {
    if(    document.forms.new_blog.name.value.length == 0 ||
        document.forms.new_blog.title.value.length == 0 ||
        document.forms.new_blog.email.value.length == 0) {
        document.forms.new_blog.submit.disabled = true;
    }
}

function check_field3() {
    if(    document.forms.new_user.email.value.length > 0 ) {
        document.forms.new_user.submit.disabled = false;
    }
}

function check_field4() {
    if(    document.forms.new_user.email.value.length == 0 ) {
        document.forms.new_user.submit.disabled = true;
    }
}