Remove Malware from Joomla website

I have a website here
www.livingwordcentre.org designed with joomla 1.7

it is presently infected with a malware. The information below was obtained from a scan with http://sitecheck.sucuri.net/

"Known javascript malware.
Details: http://sucuri.net/malware/entry/MW:SPAM:SEO
t='';}}x[l-a]=z;}document.write('.'+x[2]+'{'+x[1]+'}');}dnnViewState(); "


The malware simply runs in the background in a timer-like mode and takes my website offline after a few days.

I need someone to remove this virus for me. Please only contact me if you know what you're doing, from experience, this job will take less than an hour if you're competent enough