will Static property will have differnt values accross differnt sassion in same application ?

You can't access controls etc from a web method. You need to pass everything a webmethod needs in the method parameters. If you want controls to have their values updated then web methods are not the way to do it. To use a webmethod to update controls on the page your javascript needs to get the data it needs from the controls, pass those to the webmethod to "do something" with and that webmethod will return a result, or data, and the javascript needs to update the controls on the page with the data returned by the webmethod. If your webmethod doesn't need to update anything but needs data on the current page then your javscript needs to read that data and pass it to the webmethod via params.