Question: Im trying to add CSS to a input on keyup. If the input is empty add CSS. I've tried this...

```
            $(input).keyup(function() {
                var input = $(this).attr('id');
                if( input == "" ) {
                  $(input).css( "border", "1px solid #FB9E25" );
                }   
            });

```

Answer: 
if you mean, you want to add css if no value then, change to:

```
$(input).keyup(function() {
     var input = $.trim( $(this).val() );
     if( input == "" ) {
         $(this).css( "border", "1px solid #FB9E25" );
     }   
});

```
Try to use different name:

```
$(input).keyup(function() {
    var inputId = $(this).attr('id');
    if( inputId == "" ) {
        $(input).css( "border", "1px solid #FB9E25" );
    }   
});

```