// Class FieldDecorator function FieldDecorator(colorF,colorB){ this.focusColor = colorF; this.blurColor = colorB; this.init(); } FieldDecorator.prototype.init = function(){ this.onfocus = this.activate; this.onblur = this.deactivate; this.deactivate(); } FieldDecorator.prototype.activate = function(){ if(this.style){ this.style.backgroundColor = this.focusColor; } } FieldDecorator.prototype.deactivate = function(){ if(this.style){ this.style.backgroundColor = this.blurColor; } } // Page code: Object.registerClass("input",FieldDecorator,["#FF0000","#00FF00"]);