HTML make <option> invalid

Question

I have the following piece of code in a contact form for a site I am designing:

<select id="Category" name="Category">
    <option value="0" selected="selected" disabled>Category</option>
    <option value="1">General Info</option>
    <option value="2">Booking</option>
    <option value="3">Auditions</option>
</select>

I would like set the menu such that the user cannot leave category as the selected option. Is there any way to do this with HTML? If not, how would I do it with JavaScript?

Thank you

Answer 1

When the user click on any option, he can´t return the first one back. But he can submit form without change, then you need to validate via JS.

It's quite simple,

function validate() {
    var select = document.getElementById('Category');
    return !select.value == 0;
}

And the form in HTML:

<form onsubmit="return validate()">...</form>