How to call .js file in button click event

Jitendra,

You can use Jquery.getScript method to load the javascript on demand.

http://api.jquery.com/jQuery.getScript

$.getScript('ajax/test.js', function(data, textStatus)
{
        console.log(data); //data returned
        console.log(textStatus); //success
        console.log('Load was performed.');
});

If you don't want to use jquery then refer the below urls.

http://www.javascriptkit.com/javatutors/loadjavascriptcss.shtml

http://ntt.cc/2008/02/10/4-ways-to-dynamically-load-external-javascriptwith-source.html

http://www.ejeliot.com/blog/109