如何使用JQuery / Javascript检查选择框是否为空

Using JQuery Mobile I have a select box that is being populated dynamically from a database. As of right now the population of this check box is working flawlessly. I have added functionality that consists of a button which calls a function via an 'on click' event. The job of this function is to know whether this particular check box has been populated or not; if it hasn't then it will simply not do anything, but otherwise it will run smoothly. My problem is determining whether or not this select box is empty or not.Using JQuery Mobile I have a select box that is