如何从html页面[javascript]调用webservice方法而不刷新页面

I have a webservice which will return a value . Here my requirement is, I need to call that webserive from an index.html page , that page have a html submit button . On that button click I am calling a javascript. from there i want to call the web method. how can i achieve this.I have a webservice which will return a value .