How do i grey out the input field and the submit button

I want to grey out these two things the song input field and the submit button until the user enters and artist. Is there an easy way to do this via JQuery.

the id of the artist input field 开发者_JAVA百科is #request_artist

You can do something like this:

var artist = ('#request_artist');
var song = ('#request_song');
var assubmit = ('#request_submit');

song.attr('disabled', true);
assubmit.attr('disabled', true);

artist.change(function() {
  if(artist.val() > 0) {
    song.attr('disabled', false);
    assubmit.attr('disabled', false);
  } else {
    song.attr('disabled', true);
    assubmit.attr('disabled', true);
  }
});

for the input field, the submit button should be equal $('#request_artist').attr('disabled', true);

The one liner code would be :

     <input type="text" name="name" value="" id="txt1" />
     <input type="button" name="name" id="btn1" disabled="disabled" value="Submit" />

<script type="text/javascript">

            $("#txt1").keyup(function () {
                $("#btn1").attr("disabled", $.trim($("#txt1").val()) != "" ? "" : "disabled");
            });


</script>