I'd like to replace the height value in the following query string using jQuery:

/GetImage.ashx?w=1200&h=600&f=1&IDMF=1d5f1a45-92ac-40e9-8c8c-dc470ac85e2c

so that the url is instead:

/GetImage.ashx?w=1200&h=400&f=1&IDMF=1d5f1a45-92ac-40e9-8c8c-dc470ac85e2c

I have no access to the html on the site, hence the strange request.

Thanks

Emma