Replace the parameter in URL & refresh the page

Question

My Default URL will be like

http://localhost:4444/index.html?file=sample

And I have a drop down list with various filenames, I want to replace the parameter sample by clicking drop down list.
For each and every change the URL should be altered with existing parameter.

I Tried with following,

location.href = location.href + "filename" ;

But it won't replace the filename.

Answer 1

You can try this:

location.search = location.search.replace(/file=[^&$]*/i, 'file=filename');

location.search property holds only the query part of the URL so you don't have to worry that any other parts of the url (e.g. domain or hash) will be modified.
Also, the regex will replace only the file parameter. It is useful when you'll have some other parameters in query.