I'm trying to set the background-color and color of a TextField (to mask a password) on a checkbox click event. My best try:

Code:
var hidePass = new Ext.form.Checkbox({
                xtype: 'checkbox',
                boxLabel: 'Hide Password',
                name: 'hidePass',
                handler: function (checkbox, checked) {
                    if (checked) {
                        pass1.fieldStyle = 'background-color: #ddd; background-image: none;';
                    }
                }
            });
this code doesn't work. No errors are thrown. I'm not sure where to go from here. I've searched everywhere and can't find anything like this. I can't find any properties or methods to change the style that works.